Steve, excellent discussions on smoke. But here I just want to put in my two cents worth, the other threads were getting pretty big.
I use burlap, clean, untreated burlap. I also heard that using the dried Staghorn Sumac flowers was good. I dried some of those (I have many Staghorn Sumac trees on my property) flower heads. I have never seen a smoker burn for so long. I have worked for 3 hours out in my apiary one day, and between the burlap and the sumac flower heads, my smoker was still smokin'. Couldn't believe it. But I have not run out of smoke at any time now I am working the bees. Not to say that I use the smoke, but I can see it smoldering away, slowly, surely. Have a wonderful day. Cindi