Clean Up Meaning

(intransitive, idiomatic) To make a large profit; to win by a large margin, or to win a large amount, especially in gambling. Also clean house.

Example: 2013 August 10, “Can China clean up fast enough?”, The Economist, volume 408, number 8848:
  At the same time, it is pouring money into cleaning up the country.
  Clean up your room.‎
  He sure cleans up nice.‎
  Man, he sure cleaned up last night at the blackjack table.   The investors cleaned up when the stock hit the roof last year.‎