Clean the oven with baking soda and vinegar, no harsh chemicals
A baking-soda paste softens even old grease overnight.
1
Mix half a cup of baking soda (about 125 g) with 3–4 tbsp water into a thick paste.
2
Spread it over the cold walls and floor of the oven, avoiding the heating elements. Leave overnight, or at least 8 hours.
3
In the morning wipe it off with a damp sponge. Where white traces remain, spray with vinegar — it foams and dissolves the leftover soda.
4
Wipe with a clean damp cloth. Soak the racks overnight in a bath of hot water and baking soda.