Over time rust stain can permanently etch into porcelain. 24ActionPlumbing have a few simple tricks of removing rust stain.
Abrasive Scouring Pad:- Many of us are used to the rough side of the two color scourging pad. This kitchen item has a much tougher version available (check your local home depot) which can be used to remove rust stains around toilets and tub. The scouring pad can be reused several times, it also requires no chemicals.
Wet Lemon Juice and Salt:- This is a potent combination with enough application time this can remove rust stains. This combination works best on flat surfaces such as around toilet, tubs, and sink.
Chemical cleaners:- If you chose to use something a bit stronger for removing rust stain, you can always try a chemical cleaner. when choosing a cleaner look for a cleaner that contains hydrochloric acid and is safe for use as a tub and tile cleaner. Always follow the safety instructions carefully.