After the grates and panels have soaked, take them out and scrub them thoroughly. A long handled grill brush offers added leverage. For really stubborn gunk, a paste of vinegar and baking soda helps the brush scrub off the worst bits. Rinse them clean. Take care to thoroughly dry cast-iron grates. Now’s a great time to inspect porcelain grates for chips that may lead to rust later on.
If the grates are really dirty, soak them a second time to help soften and remove more gunk without expending extra elbow grease. Or, try the new Sienna Grilltastic Grill Steam Cleaning System. Fill this electric scrubber with water, plug it in and in seconds the combination of the dishwasher-safe stainless steel brush head and hot steam will be blasting grease from your grates. (It cleaned our GH Test Kitchen grill so well, our recipe testers asked if they could keep it.) Finally, rinse the grates well and let them dry.
Clean the bottom of the grill with a soapy sponge. Once all the chunks are gone, scrub the bottom with a sponge or scouring pad and soapy water to remove any built up grease or grime. Lots of drippings and food scraps tend to build up under the burners of the grill. Pay close attention to this area and clean it as much as possible to avoid corrosion.