I busted out the Char-Griller the other day to do some actual grilling instead of smoking. I usually grill burgers, brats and the such on my gas grill, so the char-giller hadnt had a fire in the top section for quite some time. Well over the last year or so I've done lots of offset smokes so there was a bunch of black sticky grease in the bottom of the grill. When I lit my coals in the grill section, i ended up with a nice hot grease fire... complete with stinking thick black smoke. I just let it burn out for a while and eventually it burned up all the residue. Its clean as a whistle now...So I think this will become a maintenance procedure for my offset smoker. just light some coals up top and let it burn clean....It also helped get the grill grates clean too, it burned off all the stuck on junk.