I have a high-temperature home electric Pizza oven. Despite my best efforts to keep it spotless, There are places (stainless and glass surfaces) where spatters of oil/grease have become hard baked on, to the point where they are shiny and hard.
I am struggling to find a product that will remove this stuff, it's so hard that it could be scraped off with a blade but I don't want to damage the surfaces. I've tried general oven cleaner, which did have a cleaning effect but won't touch this stuff. Tried some harsher stuff like acetone, thinners etc; no effect, baking soda; nothing.
Even tried "Pyrolytic" cleaning (i.e full temperature: 400C) but that's angered it and made it harder!
EDIT: This appears to be "oil polymerization"