Push the Friggin Button
It's not rocket science. OP is wasting time trying to clean a dirty oven, had it more than 2 years, and it wasn't clean then. That's a whole other issue, shudders at the thought not cleaning when moving in . OP used "home-made" cleaner, but it won't work on the oven glass. Why is it so hard to turn on the self-clean feature? Even more astounding are the comments, only mine mentions using the self-clean. The others are flailing away with various and sundry suggestions.