I am in the woods most of the summer and have a camp fire each night. I just put a rock in the fire until it is glowing hot. I take it out with my hotdog fork and set it on another rock. Then I get a drop of oil on a saftey pin or paper clip and touch it to the hot rock while sucking the vapors through a glass pipe bowl.

I have never gotten higher smoking oil in years. My buddy was using a small piece of charcol that they use in hookahs. Being the cheap skate that I am I decided to try the hot rock and I think it works better than the charcol. You don't get any taste from the charcol and don't suck any ash. I just keep putting the same rock back in the fire and using it over and over.