I never have an issue with the racks messing up the dishwasher, and it gets them cleaner than by hand. If you have a black interior, with a pretty new smoker, you're probably using too much wood. It's creosote buildup. I broke down, after about 6 months of 1-3 smokes per week, and cleaned the inside with E-Z Off. I did have to re-season it, but it got rid of the big buildup. Up to that point, I'd never cleaned the shelf racks, so they got a dose, too. Now, I actually only run them through the dishwasher every 2-3 smokes.