Ash with the grease then scoop out. If the buildup is substantial I'll use the weed burner to burn it up some. You want all the vents open and your still going to put the weed burner out by burning all the O2 up. Make sure to stop gas immediately. Then relight and repeat until you are good with the burn off.
Oregon Ducks Ugly Drum Smoker! - Smokey Joe Gold with Mini U.D.S. mod