I hope Puzzdre doesn't mind me hijacking his thread...
My first voyage into direct-die cooling was a K6-2 with the top two inches of a plastic pop bottle siliconed onto it. I added 14ml of water, and ran it for about 20m before I started getting air bubbles on the core. I didn't have a waterpump yet (and still don't have a decent one...) so I was basically just playing around.
I have since chipped the core, and it only works as a 166@3.5V (was originally a 350). Oh well. >