Sorry, I missed what happened, etc., so I hope I'm not speaking out of turn, but I've only ever used soft scrub. If was real stubborn, I'd take a hot dish rag and lay it over the burner spots and let it "soak" a few times, then scrub, with one of those Choir Boy scrubbies. It's got a mesh like overlay with a yellow sponge within.
Either way, glad you got the spots off!