Today a got really bored, so I started throwing crap into the micrwave to see what happened to it. I am not going to post pictures. I will just advise things to try
Eggs
a fluoresent light bulb (rings work best)
A set of small bulb christmas lights (Set will be destroyed, use an old set)
A Bar of soap in a shallow dish of water
A CD-R
a Ketchup packet
and of course...
Aluminum foil