A drug produced by fermenting human urine and feces in a bottle. A balloon is put over the bottle and it is all let sit in the sun. After a few days "cooking" the user removes the now vapor filled balloon and huffs the vapors, leading to a trip-like experience.
Common slang - Chim-chim, Butt Hash and Thai Fighting.
The Jencum is almost ready, lets give it to Larry.