Cover both halves of the lemon in salt by pouring one tablespoon of salt onto each half.
Next, use the lemon as you would a sponge and rub it across the grill grate. The lemon's acidity combined with the salt's abrasiveness will work quickly as a natural cleanser to break down the grill's grease and cut through residue.
Finally, fold a towel or cloth in half and wet with warm water. Wipe down the grill grate with the wet half of the towel and then dry it with the other half. And there you have it, a grill that's ready for you to enjoy again at your next BBQ!