clean as a whistle

blow the whistle

To disclose information to the public or to appropriate authorities concerning the illegal or socially harmful actions of a person or group, especially a corporation or government agency.

clean as a hound's tooth

Very clean.

clean break

The complete termination of a relationship, or an exit from a situation.

clean hands

Freedom from guilt, especially from the guilt of dishonesty in money matters, or of bribe-taking.

clean money

Money that is legally or honestly gained or earned.

clean someone's clock

To defeat someone decisively, in a physical fight or other competition or negotiation.

clean up

To become clean, handsome, smart in appearance, e.g. for a special occasion, especially when it is out of character to be seen as such.

clean up one's act

To reform; to improve one's habits.