Gator, I don't remember what was in the can, but it was smaller than a coffee can, but not by much. A small coffee can would work just fine, though.
Chris, I have not had to unplug the soldering iron with ordinary wood chips. The trick is to not smoke cheese for too long. It really soaks it up.
Also, don't smoke huge chunks of cheese, or you will have smoke on the outside parts, and not on the inside. I cut my cheese into pieces not more than an inch -- usually less than that. That way, when you serve the cheese, every bite has the same amount of smoke flavor.
Here is a shot of a small cheese smoke I did just for myself. The pieces were between 1/2-inch and 1-inch thick. That seems to work best, to me.
I need to get a grate just for cold smoking, so I don't need the foil.