Remove oven racks and soak in warm water with dish detergent for 2 hours
In the meantime, mix 1 cup baking soda with 1/3 cup water until a paste forms. Use a scrubber or dishrag to coat all surface areas of the oven with past. Let sit overnight.
Scrub racks with a stiff brush. Rinse and lay flat to dry.
The next day, use a spray bottle filled with vinegar and a nonabrasive pad to gently scrub away the baking soda sludge from the oven.
For areas with baked-on grease, gently scrape with a spatula or putty knife. Wipe surfaces clean with a microfiber cloth and aim to retouch in 3-6 months