devil’s dandruff
n.— «Frank graduated to smoking crack, sometimes calling it by its slang name, the devil’s dandruff. He was trying this drug business on, getting used to it.» —“Bowed by Age and Battered by an Addicted Nephew” by N. R. Kleinfield in New York City New York Times Dec. 12, 2004. (source: Double-Tongued Dictionary)