hmm from waht i read frmo KYA's post about his experience, i think ive experienced it too, although i never thought it was anything like negative ions or ozone.

my friend was cleaning her pipe, and she soaked it in a bit of alc, and then rinsed with water, and afterwards when we smoked, it kept making an almost popping sound, which sounds like what KYA is experiencing. I just assumed that it was still wet on the inside or something, and taht the heat frmo the lighter is just evaporating the liquid