Hi All, I have a question concerning cleaning the interior of my upright gas water smoker. I keep my food grills / grates super clean. I soak them and scrub them down after each smoke. The water bowl is always lined and cleaned after each smoke as well. What do I do about the inside of the smoker itself? It just keeps building up that sticky residue. Should that be cleaned off every now and then or do I just let it go?