Here's what you'll need: Dish gloves, baking soda, vinegar, dish soap, water, a spray bottle, a sponge or cleaning cloth, a scraper or spatula, paper towels, bucket or bowl and (optionally) a vacuum cleaner.
Remove the racks from your oven and wash them in warm, soapy water. Some oven racks are dishwasher safe, but check your oven manual first to make sure they won't be damaged in the dishwasher. Dry the racks and set them aside.
Moisten your sponge or cleaning cloth with warm water and wipe away the baking soda paste. Use a bucket or bowl full of warm water to rinse the sponge or cleaning cloth as you're removing the baking soda paste. For any stubborn messes, use a scraper or spatula.
Fill a spray bottle with one part vinegar and one part water. Spray down the oven and wipe away leftover baking soda paste with paper towels or another cleaning cloth. You can use a handheld vacuum or attachment to remove any remaining clumps of baking soda.