I am running out of ideas on how to remove some really hard water stain on my passenger side window. Chlorine stains are really stubborn. Heres just some of the stuff I tried to remove it that didn't work: glass cleaner, acetone, alcohol, polish, nail polish remover, zap degreaser. I tried scrapping it off with a single sided blade and it seems to be working little by little. I mean I haven't seen anything like this and about to give up. Any input which I can try out? Thanks.

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