The phrase "cleaned up one act" denotes improvement or rectification of one's behavior or circumstances. Antonyms for this phrase, therefore, would connote the opposite or deterioration in one's behavior or situation. Some antonyms of "cleaned up one act" could include "relapsed," "deteriorated," "regressed," "backslid," "deteriorated," or "broken down." These words suggest a downfall or a return to a previous negative state, as opposed to improving oneself or one's situation. It is important to recognize that these antonyms do not necessarily mean that one can never improve again, but that there has been a setback in the progress made.