First, thanks to Permies people for furnishing the inspiration for me to become soap-less.
This thread inspired me a couple years ago to go shampoo-less and soap-less. Well, let's say 98% less of that stuff now, because I still wash my hands as needed with soap, and very rarely use soap on other body parts, only in the event of major dirtiness.
I'll describe the process of my change here, some advantages and disadvantages, and some things I discovered on the way, including the use of pumice stones.
When I started going soap-less, the first couple weeks I felt a bit itchy, but my body adapted and I haven't looked back. Hair is fine, and body is fine. I felt completely "normal" again within a few weeks. Less expense, fewer chemicals: win-win.
An unexpected benefit of soap-less living is that there has been FAR less mess and cleanup necessary in the bathtub/shower. I hardly have to clean at all there now, if I'm the only one using it. Unfortunately, it's hard convincing family to also go soap-less!
One disadvantage of soap-less living is that I don't exfoliate as much. I guess soap might soften the skin so that the outer layer rubs off more easily. Just rinsing and light rubbing with water doesn't seem to accomplish this unless I do a long warm soak. So when my skin starts seeming too "thick", or looks a bit grayish, then--the next time I take a warm bath or a hot shower--I will rub my arms, legs, and face with, say, a towel that is a bit rough. That'll get the excess skin off, so I feel "baby-fresh". Might help to have a little strainer in the tub drain in order to catch and discard the skin bits.
As part of my soap-less journey, I discovered the effectiveness of using pumice stones instead of soap. I read that ancient Romans used pumice stones and skin-scrapers instead of soap. I tried pumice stones, and found that they work great at getting tough stains (like dried paint or oil or ink stains) off of fingers. Dried paint on fingers seems to just dissolve when rubbed with a chunk of pumice. Just avoid rubbing the more delicate areas of skin too hard, like the inside of the wrist, because you might break the skin there. Pumice "sticks" are available in a lot of hardware stores in the cleaning section, and natural pumice stones are available very cheaply at Mexican stores where I live. Pumice is sold for the use of cleaning scaling off of toilets or other hard surfaces, but now I mostly use it for hand-washing.
I definitely encourage others now to go soapless. No soap, no problem!