Green’s Dictionary of Slang

cleaner n.

(US) a successful swindler.

1924

D. Hammett ‘Zigzags of Treachery’ in Nightmare Town (2001) 121: She went back to the bunko game [...] She was good at it, I’m telling you — a real cleaner.

In phrases

put the cleaner through (v.)

(Aus. gambling) to impoverish.

1966

J. Holledge Great Aust. Gamble 38: But to punters [...] a greater feat than Peter Pan’s victory was that of Betting Billy in ‘putting the cleaner through the bag boys’ to the tune of a cool £200,000.