So I like this idea, mostly because I hate how quickly scrubbing sponges get so moldy and smelly, but to really make this product worth the effort I'll put into it, I think I'd try to modify two things:
Use some kind of coarse, durable
thread, so the stitches provide an abrasive textured surface?
Rather than fold and stitch an already serviceable-sized towel like in the tutorial, I'd stack up many, too-small-to-use bits of fabric and sew the stack together, to make the thick pad.
Do these changes make sense, or am I missing the specific magic of the Zokin as described?
Growing on my small acre in SW USA; Fruit/Nut trees w/ annuals, Chickens, lamb, pigs; rabbits and in-laws onto property soon.
Long term goal - chairmaker, luthier, and stay-at-home farm dad. Check out my music! https://www.youtube.com/@Dustyandtheroadrunners