Baked-on carbon comes off with a caustic gel and dwell time, not with abrasion — scouring an oven scratches the enamel it is meant to clean and makes the next one worse. Racks come out and soak while the cavity is treated. Fridges are emptied, shelves washed separately, and the drip channel at the back cleared, which is the part that smells and is the part nobody finds.