I generally try to avoid traditional soaps (saponified oils). They’re only soapy at in basic solution, and skin is naturally a bit acidic. Even for washing di

I generally try to avoid traditional soaps (saponified oils). They’re only soapy at in basic solution, and skin is naturally a bit acidic. Even for washing dishes, there are mildly unfortunate interactions — try mixing Dr. Bronner’s soap with any acidic food. You get a gooey mess that isn’t soapy. On the other hand, I suppose that traditional soap residue that anyone with normal stomach acid manages to eat will turn back into free fatty acids. (Skin is, in general, rather more sensitive to bases than acids. Even a fairly mild base will make skin feel unpleasant and a bit slimy, whereas holding an orange slice (quite acidic) is not particularly irritating to intact skin.)