MB3 162a: Drying Yourself and Using Liquid Soap on Shabbos (326:9-10)

Washing your hands, feet, and face on Shabbos. Drying one's hair on Shabbos. Going to the mikvah on Shabbos for Takanat Ezra. Using a bar of soap on Shabbos violates ממחק (smoothing). Using liquid soap on Shabbos.