Oven cleaner: I haven’t tried this one but perhaps someone would like to. I once tried siting a dish of cloudy ammonia in the oven overnight but all it did was stink the kitchen out.
Oven cleaner: 3 parts cloudy ammonia to 1 part water. Fill spray bottle. Preheat oven to warm then switch off. Give spray bottle a good shake and spray interior oven thoroughly. Leave overnight and clean oven next morning.