Use a wire brush for gentle brushing along the grates or cooking dishes so you're able to remove any debris. It may also help to remove carbon buildup on the grill surface. If it becomes hard to clear the buildup with the wire grill brush, use the putty knife to remove the dirt from your grill. Make sure your grill is off and cooled. Start by removing the grill grates from the grill and steam the inside of the grill with a metal brush attachment. The debris will start coming off as you go. With a damp cloth, pick up any tar that is collecting on the bottom.