The expression “taken to the cleaners” means: Defrauded; despoiled; mulcted; flimflammed; stung; played for a sucker; also punished or severely defeated.
This is merely a modernized form of the slang term “cleaned out,” used by some of our great-grandfathers in the early nineteenth century.
The New and Comprehensive Vocabulary of the Flash Language, written in 1812 by James H. Vaux, defined the older phrase: “Said of a gambler who lost his last stake at play; also, of a flat (dupe) who has been stript of all his money.”
The modern form, however, introduces a subtle play on words in the secondary meanings of punished or defeated in the suggestion that he who has been cleaned has been sent through a washing machine or has been subjected to the machinations of a dry-cleaning establishment.