The hangover remedy involving the acts of drinking large amounts of liquid, and vomiting it all out in a routinely matter. Involves multiple repetitions to achieve a successful cleanse.
"Man, I drank way too much last night. I better start cleansing now to get rid of this hangover."
"Dude, that's like your fourth trip to the bathroom this morning? What the hell are you doing in there?"
"Don't worry, bro. I'm just cleansing."