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Episode 55: Groundz Pewter Casual Clays Slip-Ons

Updated: Jul 26, 2022

Introduction: These were one of my first pair of slip-ons. While compared to what I usually wear they give a more dressier vibe, they can easily be be dressed up and dressed down.

The grounding plug is a huge bonus for me as someone who prefers to spend as much time barefoot as possible as I can ground even while wearing a nice pair of shoes.

Their subtle yet classy look can work for someone who is not fully bought in to the barefoot world but is looking for a comfortable and dressy slip on. Groundz offers Men and Woman's slip-ons as well as Woman's sandals all which are grounded. They also have a men's model sandal model coming in the future.

Their website can be accessed here.

You can use our code TBSR for 5% off.

Disclaimer: These shoes were given to me to review, however my opinion is my own. This page uses affiliate links, and by purchasing from an affiliate link, I will receive a small commission which doesn't cost you anything. Thank you, and enjoy the read!

Company Overview:

We're a small team of health and fashion enthusiasts with a passion for creativity. We want to bring you innovative products that are functional, comfortable, fashionable and healthy to wear. We want to increase the awareness that what we put on our bodies is just as important as what we put in our bodies. More natural functional fashion that makes a difference. Let grub and garb be thy medicine 😋 We set out to create not only an anatomically correct shaped shoe, but also one that’s made of all natural materials. We believe we have crafted a shoe that’s functional, healthy, natural, grounding, comfortable and stylish. Wearing an all-natural foot shaped shoes may take some time getting used to. They look different and feel a little different, but we are pretty confident that after giving your body a bit of time to adjust, you will never wear “traditional” shaped shoes again. Wearing foot shaped shoes will strengthen your feet, correct your posture and help in reducing foot, shin, knee, hip and lower back pain.

Our shoes are based on the Yemeni shoe that has 700 years of history and tradition, and are crafted by artisans whose trade has been passed down generation to generation. Using a unique hand-stitched sole construction and all natural materials, we took the classic version and redesigned it to incorporate a wide toe-box, a “zero-drop” flat thin sole, and a grounding copper plug. Our shoes’ unique construction allows your feet to breathe and disperse sweat, preventing odors, and can be worn with or without socks. The result is a beautifully made grounding shoe that's healthy, comfortable, flexible, versatile, yet durable and made to last for years.

Manufacturing and Sustainability:

Clays are produced in small batches, by hand with each pair taking days to complete. We start with cutting and stitching the leathers that form the upper part of the shoe. The upper is then pulled over our proprietary last (mold). Lasting is the process of wrapping the leather uppers over the cast mold of a foot and gives the shoe its shape and fit. Clays are hand-lasted allowing the craftsman to form and mold the leathers perfectly and according to the nuance and malleability of the specific leather used.

Our last is unique in that it is shaped with:

  • Wide toe box – giving your toes freedom, “un-squishing” your feet and relieving bunions.

  • Zero drop and minimal toe spring - keeping the foot in a natural position, strengthening muscles of foot and legs, and so improving body posture and gait.

  • Grounding plug - that neutralizes electrical charges and may reduce inflammation, pain, stress, improve blood flow, sleep and more.

Next comes our buffalo vegetable tanned pliable sole that allows your foot to feel the texture of the ground, activating all the healing pressure points on your heels, arches, toes and especially the balls of your feet. The sole is then attached to the upper using an all natural traditional clay paste which is what we name our Clays after! Other manufacturers use synthetic glue for this purpose. We apply our natural clay not only to the sole, but also to the inner lining which further allows any build-up of static electricity to be discharged.

The edge of the sole is then cut by skillful hands to follow the perimeter of the shoe and refine its shape. Once the sole is applied, the upper and sole and insole are sewn together by hand using beeswax soaked cotton thread. This stitching makes the shoe incredibly durable and gives it its distinctive look. This process is unique to our style of shoe and differs from most modern shoes that are usually glued together. Our unique style of construction forms a shoe that will last a lifetime. Shipping and returns:

Under-groundz members get free standard shipping and returns on every order every time!

Just need to sign up to their mailing list here.


Grounding or Earthing is putting the body in direct and uninterrupted contact with the earth. Grounding removes excess electrical charge on an object by transferring electrons between it and another object of substantial size, in our case – between our body and the earth.

Grounding is in our DNA:

Human beings, and all living organisms, are bio-electrical in nature. We produce positively charged free radicals during normal metabolism which place oxidative stress on the body. As for all electric machines, our body needs to be grounded or “discharged” for proper functioning, health and well-being.

Our modern lifestyle insulates us from the ground and surrounds us with electricity from cables and wireless transmissions. We insulate ourselves the majority of the time by wearing insulating synthetic shoes, by living in insulated homes and by driving insulated cars.

This insulation creates a positive electrical build-up. This charge turns out to be quiet harmful to our bodies, disrupting the nervous system, creating inflammation throughout the body (positively charged free radicals have no way to be drained) and raises our cortisol levels.

Grounding is a therapeutic technique that involves finding ways for your body to plug back in to the Earth, an abundant source of natural negatively charged electrons, and drain this excess positive charge. One way to plug back is by wearing grounding footwear. Studies show that this helps with reducing blood pressure, inflammation, regulate sleep, blood-sugar levels, and more.

Natural Benefits:

Studies show that being directly connected and “plugged” into the earth can:

  • Eliminate excess electrical build-up and neutralize harmful EMFs

  • Reduce inflammation and pain

  • Normalize cortisol levels and reduce stress levels

  • Regulate biological rhythms and improve sleep

  • Improve circulation

Natural Conductive Elements:

There is a good reason why it feels so good walking barefoot on grass at the park or on sand at the beach. By directly touching the ground, we absorb earth’s electrons and tune in to earth’s natural frequencies

We created our shoes to allow uninterrupted electron flow from your feet to the ground. We use premium eco-friendly natural materials throughout, to make them healthy, comfortable, simple and grounding!

First Impressions:

  • Gives a dressy and casual look at the same time.

  • Stiff at first especially the sole but after 2-3 times of wear it breaks in gently as the leather stretches.

  • Super easy to slip on.

  • Has a nice smell of leather and very authentically made.

  • My feet were sitting a little over the bottom of the shoe until they stretched.

  • Really liked that I didn't need to wear socks since the shoe itself minimizes odor and disperse sweat.

  • This shoe was built to last and endure, the attention to detail is quite good. almost like you are wearing a piece of art.

  • The copper rivet is cool and you don't feel it at all.

Sizing and Fit: **My foot is approximately 26 CM long and 10.1 CM wide with my second toe being the longest.**

Clays should fit snug, even tight at first as they will stretch. They will “break in” and take the shape of your feet within days to a few weeks depending on frequency of wear. If you are between sizes, we recommend sizing up, especially if you intend to wear the shoes with socks.





Toe Box






























11 cm

I ordered true to size. I am generally a size 9/42. The shoe fits my fit perfectly without to much extra space in the heel or the toe box which can be a problem with many slip-ons. I did feel my foot was wider then the bottom of the shoe but as the shoe stretches that problem gets solved. Plenty of wiggle room in toe box. I have a high volume foot and it gave me plenty of space while still being an extension of my foot.

Upper and Lining:

We use 3 types of leathers to make our Clays:

The Upper, which is the top part of the shoe, made of cow leathers, primarily vegetable-tanned or semi vegetable tanned. Depending on the style, and going from softest to firmest, we use Suede, Nubucks and smooth leathers, all of which are durable, robust yet malleable to form and comfortable to wear.

The sole – This highly breathable Water buffalo leather, the sole of the shoe, made using a very traditional and all natural vegetable tanning process, provides the base of our shoe. This naturally anti-microbial, durable and comfortable leather will mold to your feet and keep them cool fresh and dry, preventing odor, whether you wear them with or without socks. Buffalo is porous and allows you feet to breathe and disperse sweat. Your shoes will never have any funky odors.

The Lining – is the leather that is on the inside of the shoe and touches your foot. It’s a vegetable-tanned, all natural leather that is soft and gentle on your skin. We apply a layer of clay (no synthetic glue) between it an the upper, then sew the two together. A breathable layer that will guaranty no funky odors here!


  • The outer is quite stiff compared to most barefoot shoes.

  • it has decent ground feel for something stiff and loosens up over time

Weight and movement:

  • Extremely comfortably and easy to slip on.

  • With a high volume foot i find the shoe a good extension of my foot allowing me to comfortably walk and be on my feet for hours.

  • This is a dressier shoe and it is not quite as flexible as some other barefoot shoes.

Packaging and Extras:

  • Comes in a nice recyclable hemp bag with a card .


  • Upper: Natural Nubuck Leather (a version of suede which gets better over time)

  • Interior lining: Natural soft leather with a clay barrier.

  • Insole: Water Buffalo leather

  • Outsole: Water buffalo leather

  • Stitching: 100% cotton waxed thread

  • Weight: 470g

  • Stack Height: 10mm

  • Available sizes: 23-48

  • Price: 179$ inc. VAT

  • All natural renewable materials.

Care instructions:

We recommend cleaning your sandals with a natural leather conditioner. To make one yourself, mix one cup of warm water with a few drops of soap and a couple drops of vinegar. Dip a cloth into the mixture, wringing it out so it's damp and not wet. Wipe down the sandals. Allow the leather to air-dry once finished. Future Improvements: A more flexible sole. While the shoe does stretch over time, the outsole mostly stays the same.

Where and How to Wear.

I have worn this to a wedding and have gotten loads of compliments on it and even pulled it off with casual jeans and shorts. It can be dressed up or dressed down.

Conclusion: The main benefit for me here is grounding, which makes me wear these shoes for any occasion that requires me to just be a bit dressy. The fact that i can ground and still look good is the game changer for me.

The beautiful soft feel of the leather against my feet feels really nice and knowing I'm wearing something that's sustainably made and made from natural materials is the punch line. Their website can be found here and they offer men's slip-ons and Woman's slip on sandals all which are grounded.

Can use code TBSR for 5% off.


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