An oxymoron for sure: bleach stain, but I somehow stained my 66 year old enameled steel bathtub last night. I had splashed bleach in the tub to disinfect it, then did a half assed job of rinsing it all out. When I looked a couple hours later a rust colored stain had formed toward the back, continuing as a trickle toward the drain. I've tried scrubbing, hard, with comet and even steel wool to no avail. Its like I caused a chemical change, rust-like, in the enamel. Any suggestions? (and no, i havent tried bleach!)