After about 30 minutes, turn the heat off and let the grill cool down. Wipe things down to remove any lingering residue and you should be good to go. The grill grates should have turned a bronze or dark brown color if they are metal or a darker brown/black color if they are cast iron. For cast iron grates, the oil will have penetrated the pores of the metal and created a smooth non-stick surface that will be perfect to cook on.
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.