the 5 minute ones are amazing, see if
This Link works to the category at extremeglow.com
I"ve got a bag-o-fun from them right here waiting for it to get dark out for halloween
I have put them in the microwave for a few seconds before, just occurred to me that warming up the insides would give them a little more Oomph. It does work, even with ones that are almost used up. But if you manage to increase the pressure inside the tube enough, and or weaken the plastic with spots of heat it will go boom inside your microwave.
the insides are mostly concentrated hydrogen peroxide, at least thats the chemically active part that you wouldn't want to get in your eyes and such. (beyond the sharp broken glass bits) There was an article recently that decided that the stuff had been around long enough, and enough people had been exposed to the insides for them to conclude that it wasn't dangerous beyond the potential for some irritation or rash like nastyness. So if you do get it on your hands, wash it off ASAP and you should be OK. Of course, if you are not OK get it seen to.