Wash the burner pans with dish detergent and warm water, using a sponge or scrubber to remove loose food debris and as much grease and grime as possible. You can also clean the burner pans in your dishwasher.
Fill a deep cooking pot with warm water. The pot must be large enough to hold the burner pans. If necessary, clean burner pans one or two at a time.
Add 1/3 cup of baking soda. Stir thoroughly with a large spoon.
Place the pot over a burner and bring the liquid to a boil.
Place the burner pans in the boiling water. Allow the pans to boil for 10 minutes.
Remove the burner pans carefully from the hot water with long-handled tongs. Place them on a layer of paper towels to cool until you can handle them comfortably -- about 10 minutes.
Wash the pans again with dish detergent and warm water. Rinse thoroughly.
Dry the drip pans, and then return them to the stove top.
Wash the stained burner pans with soap and warm washer to remove as much food and grease as possible, or use your dishwasher. Dry the pans.
Pour 1/4 cup of household ammonia into a large plastic bag and add the drip pans.
Tie or seal the top, and set the bag aside overnight. The ammonia fumes loosen baked-on grease and grime.
Open the bag slowly and cautiously. Stand back to avoid the ammonia fumes, which may cause eye irritation. Rinse the burner pans with hot water. If necessary, use a scrubber to remove remaining grease and grime.
Dry the pans and return them to the stove.