I have had to do the deep clean before because of a rodent problem. Crawled up through the drip hole. After the oven cleaner, I wiped it down with vinegar, then loaded up the wood box and reasoned. I got a bolt that was pretty close to the diameter of the drip hole, and a washer which I bent slightly to match the contour of the smoker floor. JB Weld to hold bolt and washer together. When the smoker is not in use, the bolt plugs the hole. No more uninvited guests.