Before you start scrubbing, brush or vacuum out as much dry ash as possible (a shop vac works well for this). Hose down your grill and lid, inside and out, to rinse out any residual ash. Now start scrubbing (with gloves on). You need hot water, a plastic scour pad, and either dish soap or degreaser. If you use dish soap, just scrub the entire firebox and grates with hot, soapy water, then rinse them well and dry. If you use degreaser, make sure it’s safe for food surfaces (I use Simple Green). Spray on the degreaser and let it sit for about 20 minutes to penetrate the gunk. After that, scrub everything with your scour pad and rinse well with hot water. When I use degreaser on my grill, I like to give it a once-over with hot, soapy water afterward and then rinse again.
