My three year old grandson is a huge KISS fan and he does a great Ace Frehley impression. He has recently taken to copying Ace's style during his smoking guitar bit but is disappointed he can't actually make the guitar smoke.

The boy's favorite guitar, which he calls The Destroyer, is a plastic Teenage Mutant Ninja Turtle ukulele. It has a hole in it like a typical acoustic guitar.

I have an idea about rigging up a dry ice contraption inside the hole so the guitar will "smoke". I can't have it sloshing around inside lest he get burned.

Best idea I've come up with it something like a test tube with a stopper that has a hole in it that I can either drop in or velcro inside the guitar body.

Any suggestions? 

This is what I am shooting for: