I wasn't going to spend the money for the Traeger Cold Smoker add on. I simply used the A-maze-N Smoker and frozen bottle of water. When ready to cold smoke in the Traeger, I place the lit A-maze-N Smoker on the grill, then place a couple bottles of frozen around the A-maze-N Smoker. Then place the vegetables, meats, nuts, cheeses, olive oil, flour and any thing else that might need a smoke flavor like Kosher salt or your favorite spices, Paprika. On the meats, if not already frozen, I place them in a tray which is setting on top of a frozen bottle of water. This helps to maintain a cold temp.
In the picture, the A-maze-N Smoker is shown with the frozen water bottles around it. One bottle is on the lower shelf while the second bottle is on the upper shelf (warming shelf). I did not take a picture of what was being smoked at the time.