A cult classic/exploitation movie from the late 1980's. The story loosely revolves around a seedy liquor store owner that comes across a case of 60-year-old booze called "Viper" and sells it to the local bums for a dollar a bottle. When the victim drinks the booze, they either melt, fall apart in huge chunks, or explode.
Subplots also include a game of keep-away with a severed penis, necrophilia, and a bizarre love triangle between a low-paying secretary and two transients. Also titled "The Horror on Bowery Street".
This movie was once a hard-to-find gem in the VHS bootlegging circle; it now has a new lease on life thanks to a remastered release on DVD.
I watched that movie Street Trash, and it was vile. I had to take a shower afterwards.