Black money scam
The black money scam, sometimes also known as the "black dollar scam" or "wash wash scam", is a scam where con artists attempt to fraudulently obtain money from a victim by convincing them that piles of banknote-sized paper are real currency that has been stained or dyed for some reason. The victim is persuaded to pay fees and purchase chemicals to remove the dye, with the promise of a share in the proceeds.
The black money scam is a variation of what is known as advance fee fraud.