To wipe and wash up one's Musty Basement aka dirty ass. May also apply to one's arse that has been given a cream pie.
After tapping his foot in the stall, Larry was joined by a brawny mate who pumped his arse full and left Larry Cleaning the Musty Basement when they were finished.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.