Rust-Oleum Whink Rust Stain Remover | Heavy-Duty Iron Stain Remover Foaming Spray with Excellent Cling for Toilets, Showers, Sinks, Outdoor Siding | 24 oz | 4 Pack

Absolutely works to get hard water/rust stains out but has a very chemically smell. The spray bottle didn't work so I ended up pouring it out onto stains instead

On cement - turns white if not careful

The warehouse custodian used this and it kept the porcelain fixtures spotless. I bought it to remove iron stains on acrylic that had been there for years and it helped but didn't remove them completely. I was asking a lot so I'm not surprised, but I was hopeful.

I bought this to use at my brothers who has sulfur water and has stains in his tub, toilet and sinks. I sprayed it on let it sit on there for a little while and the stains came right off.

This product really whitened my quartz-kitchen sink, but did nothing for the porcelain sinks and bathtub. Caution: The bottles were well-packaged with tape around the necks of the bottles and each bottle was in a separate bag BUT they all still leaked. The shipping box was stained and each bag was wet. The product stung my hands upon removing the packaging. Also, the sprayers are difficult to use. It took forever to get any product out of the bottle and there is a stream-spray that doesn't cover much area. I prefer a wider spraying area. You also need to know that this product has a strong, toxic odor. You can barely stay in the room after spraying it.