How to remove Lime Away stains from Porcelain Tub knobs?

• Pour 8 oz. of hydrogen peroxide into a bottle.
• Add in 4 tbsp. of cream of tartar. Shake the mixture to combine it thoroughly.
• Spread the mixture over the brown water stains on your porcelain fixtures using sponge. Allow the mixture to remain on the stains for at least 30 minutes.

Wipe off the mixture using a wet washcloth. Repeat as necessary to remove any further water stains.

thank you for the question and for this answer. I did the same thing in my bathroom sink. However, time has returned the brass colored drain back to it's natural color, thank God! Next time, I will try to remember your Peroxide and COT solution.

WD40...spray on paper towel and then whip off