We recently bought our first DO and added a trivet to the bottom to keep the meat off the direct bottom. First try was a whole chicken on the wire trivet with some potatoes. I found various recipes, cooking charts, suggestions and so. Told the DW to stand back, this is a man's job and proceeded. Did a couple loads of charcoal, per instructions, and never once lifted the lid (which drove the DW crazy). Consumed a few adult beverages and sat back waiting for the I told you so's. After the predetermined time removed the lid to reveal a perfectly golden chicken. Only glitch was that the bird was so tender, it was hard to get out of the DO. And taste? OMG Simply great. Only down side is, guess who has a new job when camping?
Also did a prime rib at home outside on the patio and it also was great.
Keep using it, keep it clean and it will smoothen.