First off, I am not asking for anyone's recipe, just a little guidance. I am working on an exfoliating soap good for mechanics/gardeners/artists/etc. I know I want to use activated charcoal or bamboo charcoal (is there a difference). I also want to use pumice and coffee grounds. I have found various recipes for each of those soaps. My question is, when I combine them, should I lower the amount of each ingredient? Or would you suggest adding them all at the same rate?