LetsRV wrote:
Put a piece of alum foil across the grates (shiny side down). Close the lid and crank the grill up to high. Leave it for 15 to 20 minutes. When you open the grill, remove the foil, you will have a fine grey ash clean off.
Works like a charm on any grill I've ever tried it on.
This works every time, however, watch how long you leave it on because it can burn out your igniter or other combustable parts nearby. It's gets very hot down there with the foil on top. He's right, though. Nothing but white fluff that blows off. Easiest way I know.