Rinse the cast iron under hot water promptly after cooking.
Sprinkle coarse salt over the burnt spots on the cookware and scrub with a nonmetallic scrub brush.
Rinse the pan under warm water to remove the residue. Wash with a rag and a couple drops of dish soap. Rinse and dry the cast-iron cookware thoroughly.
Fill a cast-iron pan with 1 cup of water and 2 tablespoons of baking soda if baked-on food remains. Put the pan on the stove and bring the water to a boil. Allow the water to boil for 10 to 15 minutes. Discard the water and scrub the cookware with a nonmetallic scrub brush. Wash, rinse and dry the cookware well.