What is the origin of the idiom "money laundering" and when to use it?

The idiom "money laundering" originated in the United States during the 1920s when criminals wanted to hide the money they earned from selling illegal alcohol. They called it "money laundering" because they tried to make the money look clean, just like washing dirty clothes. Since then, the term has been used to describe hiding the source of illegal money by making it seem like it came from legal activities.