Answer:
Butch wax is a pink wax that was used for crew cuts and flat tops. The flat top haircut generally had a "front row" of hair which was neatly propped across the top of the forehead. Butch wax was applied to keep that row of hair vertically in place. ( I still have an entire jar from around 1965! My youngest son discovered it and uses it for keeping his hair where he wants it. He doesn't have a flat top, but likes the effects of the wax which doesn't give the luster of a modern gel.)