When it's a "factory" head with silica wick dry burning is okay, but not effective. Once you re-wick with cotton, you have to de-wick then dry burn, also not effective. I did go to the liquor store today to ask for the strongest cheap liquor they sold, the guy looked at me like I was crazy! I explained I didn't want to drink it, but use it for a solvent for my ecig. He then sold me some rotgut vodka and asked me if I would be able to quit vaping someday.

Anyway, I'll try to soak them in vodka, scrub with small brush, then dryburn, and hope the gunk goes bye-bye.