I had lost hope with my electric cooking plates. The white circles where completely hidden under a layer of diamond-grade burn residue that no amount of scrubbing with chemicals could even begin to remove. I found this 3€ scrapping tool and it’s amazing !!! Sorry, but I don’t have the before picture, believe me after 6 years of usage, it was bad.
People have historically used bacon grease to make soap, with lye. It’s also commonly used to seal pans against moisture, without washing them after. Also is a decent chrome polish.