rusty bong polish
Surreptitiously rimming yourself with the mouth end of a bong belonging to somobody who has angered you, or whom you just hold general contempt for. Farting in the bong makes the gesture that much more meaningful.
My girlfriend's little-shit brother left his stupid bong at my house last weekend, after spilling it on my couch no less. So I gave it a Rusty Bong Polish before he picked it up again. I hope he tastes the Taco Bell I had earlier.