I don't know snakewispera, have you ever tried to boil water on a fire. It takes a pretty good fire and a lot of time just to make coffee. I'm sure your idea would work, I'm just not sure it is going to be very practical.
Wood and paper don't burn until you reach around 400*. I think I would bake them in the oven around 200-250 for 1/2 hour. That would surely kill anything living inside of them. Of course, you want to watch them and have the fire department standing by, maybe a couple of buckets of water.