Rated X - duck butter

Sick **** man. I've heard it is under-ball sweat. Out here in Camarillo, Cali, it's the name of some local band

DUCK BUTTER - noun. Southern. smegma or semen; (also) sweat that gathers on or near the genitals. 1933 AS (American Speech) (Feb.) 48: Duck butter, n. Sperm, seminal fluid." Random House Historical Dictionary of American Slang, Volume 1, A-G by J.E. Lighter, Random House, New York, 1994.