The endothermic gas reaction takes place in two steps or stages. In the first stage, some of the methane. burns with air creating an exothermic (heat generating) reaction. In the second stage, the surplus methane. reacts with the carbon dioxide and water vapor produced in the first stage. This second stage is endothermic. (heat absorbing).
Pat the chicken drumsticks dry with clean paper towels. Cover them with plastic wrap or aluminum foil to warm them up to room temperature for 30 minutes. Preheat a gas or charcoal grill to 400 degrees F. If you are using a charcoal grill without a temperature gauge, this will take about 20 minutes.
Brush the grill grate with a brass wire grill brush for about 10 seconds to remove any large food particles. 2. Turn the grill to the high setting until the smoke stops to burn off any remaining food residue. 3. Turn off the burners. 4. Brush the grill grates clean with a brass wire grill brush. 5. Spray the grill grates liberally with vegetable oil to loosen any food particles that may still be stuck on the grate. Once loosened by the oil, the particles will fall below the grate and will be burned the next time the grill is turned on.