I would guess this stove is over 20 years old, electric with the glass cook top. Four hours, yes. I wonder what the power usage is because it gets v-e-r-y hot. And mostly, just wipe the ash out. There were a few small areas where I did scrape a bit. It didn't do much for the window on the door, though. I used a blade for that. Took about 15 minutes. Still much easier than doing it by hand and I think (not sure) you are not supposed to use oven cleaner (yuck) or it would ruin the surface.
Cool weather project is why I did it yesterday before summer arrives. It was cloudy and gray and in the 50's mostly. Saw that as a Last Chance, lol.