you "treat" the metal much like you would a cast iron skillet.
After using, clean the grill, rub a thin coat of oil (I use canola different oils provide different seal quantity) then heat to smoking point. Wipe down and repeat a few times. This will coat the metal.
Most importantly DON'T use detergents it'll ruin the seal
It is always an after thought, you finish cooking and the grill is super hot from the charcoal. Its late at night, you want to eat and relax. By the time the grill cools, you are sound asleep.
After using, clean the grill, rub a thin coat of oil (I use canola different oils provide different seal quantity) then heat to smoking point. Wipe down and repeat a few times. This will coat the metal.
Most importantly DON'T use detergents it'll ruin the seal