I was skeptical first time I saw it, but it works! Wrap bearing in damp washcloth, place in micro, use 15 second bursts till you figure out correct time. It turns the water to steam to heat the bearing, flash dries in open air, gets VERY hot, do not try with sealed bearings as it will melt the seals.
I have seen some comments about melting metal in a microwave, but it pretty much falls in to the category, for me, of 'things to do with a Microwave before it gets turfed out'.
Well, doing that, and making AOL CD's safe for humanity!
(High, about 6 seconds, or until you hear the Bzzzztttt!)
I suppose you are essentially creating a pocket of superheated steam around the bearing. I know that there has been a use of microwaves as well in Veterinary practice, to warm the core temps of animals that were hypothermic. Chalk it all up in the list of things that sound wrong but work.
One of my High School Science teachers, who spent a bunch of time in tanks in North Africa, said the the very BEST things they got when they over-ran a German position were the propane cylinders, as they could put the beer that they inevitably managed to hoard, in to a gunny sack with a bunch of stones, and vent the propane in to the sack to provide a cool beer in the Desert sun!
The paintball gun? Nope. If the continuous banging of the short bursts of CO2 doesn't cause anyone around you to start throwing wrenches, I dunno what will work better.
Buy a can of liquid Freeze, it gets used a lot for testing electronics. The Air cans for cleaning computers are not set up to draw off the liquid and spray it out, generally, and the can needs to be held upside down.