In a cold oven, place a glass dish with half a cup of full-strength ammonia. Close the oven and let it stand overnight. The next day the grime on the oven walls should be loosened sufficiently to be easily wiped away with a damp sponge.
How to Deep Clean a Kitchen Oven - Using Amonia
Cleaning your oven the easy way, With no ammonia
Would you like to have a sparkling clean oven, but procrastinate clean… :: Hometalk
Spring cleaning hacks - clean your oven with just ammonia
Household Cleaning Tricks!
How to clean your oven with ammonia.
Cleaning Oven Racks ~ very easy ~ must leave bag OUTSIDE...
Easy way to clean oven with ammonia
Spring cleaning hacks - clean your oven with just 1/4 c. ammonia, set in oven overnight, wipe clean