Thank goodness for zombie threads! I did the same thing --- boiling water, vinegar, Comet, Brillo pad, baking soda, and no closer to cleaning it than I was when I started. This does the trick. I couldn't believe it. I didn't have quite enough peroxide to cover the burned area, but even just tilting the pan a bit to cover higher-up areas was enough to let me chip off more of the burned part with a spatula. I'm a believer. Thank you, thank you, thank you, MixieArmadillo!!!