Since the skin breathes, it is important that the pores are open and not clogged with heavy fats and oils. However, the skin is also absorbent so the quality of soap is as important as the quality of food and herbs.
The vast majority of soaps are harsh detergents that have adverse impacts on our health and the environment. Some soaps are made with animal fats, lye, and synthetic fragrances. Using a quality soap is very much advised both for environmental and health reasons.