S/G is the short version for "shower gel", a substance used to clean the body while showering insted of the usual soap. It is similar to liquid soap. (see Shower Gel)

My favorite! I have always love Body Shop products, even if they are quite expensive, so all shower gel products from Body Shop. Victoria's Secret showel gels are also very good, and I am supplied by my sisters and mom from Texas every time they send us balikbayan box assorted products from Victoria's Secret (lotion, shower gels, colognes, panties, etc)
List of books: S/G