Just did some testing today of cotton balls rubbed in petrol jelly. I must say, the prep work was one of the grossest things I've done in a while, but the results were excellent. I would safely say that adding the jelly increased the cotton ball's burn time threefold. Def. plan on adding jelly to the cotton balls in my PSK
the only "down side" I've experienced with vaseline/cotton balls is having them "leak" in extremely hot weather. Those plastic 35mm film canisters are OK BUT a truly air/watertight container (i.e plastic match safe with rubber seal) works better and lessens the chance of getting vaseline on your other PSK gear (not that it would damage much).
