When receiving a hand job, the man's ejaculate land on the female's wrist and, by gravity, runs around her wrist. This creates the look of a white band on the woman's wrist. Popular because it normally requires just 2 to 4 ropes.
Stick your hand in a can of Crisco until it's lubed all around. Then insert your hand/fist in a woman's rectum until your watch tickles her stink star.