I'll never forget the state of my oven racks before I found Nano Go.
Years of roasting, spillovers, and quick wipe-downs had left a black, carbonized layer baked onto every rack and the inside of the door. Scraping did nothing. Oven cleaner sprays did a little, after an hour of fumes and a lot of scrubbing.
I'd tried the supermarket degreasers, the baking soda paste tutorials, even a razor blade on the glass. Some took the surface grime off. None touched the burnt-on layer underneath.
I know how to clean a kitchen. I just couldn't find anything strong enough for grease that had been cooked on, over and over, for years.
Then I found out the actual problem: I wasn't using the wrong technique. I was using the wrong chemistry.