I did this a few weeks ago, but I just used my GOSM. I put the can and the soldering iron on the bottom shelf, and put my cheese on the top shelves. I just ran the cord out the bottom corner of the door. The day I did it the temp was in the 40s, and the temp in the smoker stayed in the low 50s.
just buy the cheapest one you find. Surprisingly they last a long time. The boxes are a great cheap idea, but if you have ANY kind of smoker or grill to use an an enclosed space, it will work. Clean racks would be nice.
I have done 2 smokes with the soldering iron in a can.
My only comment...
I would use a NEW soldering iron. Solder has lead in it as well as rosin and other stuff that I would not want to get on my cheese. Not sure how much it would effect the taste, but I know my used soldering iron does smoke somewhat from the residue on it.
Absolutely. Use a soldering iron that you purchased just for cold smoking. I also like to place any new can to be used on an open flame to burn off all the coatings. I do this in my kitchen over the gas burner and under the range hood. Those fumes are nasty. You can also do this on your grill. I still cold smoke with this method, minus the boxes. Just works so well and it's cheap. What more can you ask for.