There are a few ways we can use to try and remove the stain. Remember that if the stain is dark and set in you might not be able to get the stain completely gone. I will show you a few eco friendly ways to clean this and a few non eco friendly ways to do this.
Eco Friendly:
- Pour a can of Coca-Cola( believe it or not but this has worked) in the toilet bowl and leave it overnight. Diet Coke doesn't have the same effect so make sure it's regular Coca-Cola. In the morning, the toilet should require very little scrubbing for the stain to disappear.
- Put on rubber gloves and dip a dampened pumice stone in baking soda and gently scrub the stains from the toilet. The baking soda provides extra abrasiveness and may not be necessary. You can try using just the pumice stone by itself first and add the baking soda for particularly stubborn areas. Be careful not to scrub too hard, the pumice stone is so effective it may accidentally scratch the porcelain.
- Drop a few denture tablets, like Efferdent, into the toilet bowl and allow them to soak for thirty minutes to loosen the stains. Scrub the toilet with a toilet brush to remove any residual stain.
- White distilled vinegar is generally recommended and is usually sprayed or poured directly into the toilet and allowed to sit for several hours before scrubbing.
Non Eco Friendly:
There is a large selection of commercial toilet bowl cleansers currently available, including acidic and chlorine-based solutions designed just to treat toilet bowl rings. Acidic cleansers might remove hard water rings but can include strong acids, such as hydrochloric acid, that may require dilution before use. Chlorine-based cleaners, on the other hand, include items like bleach that work to remove mildew rings and may whiten other stains. Not only will you need to compare between brands, however, you will also have to take your pick of powdered or liquid cleaners. Powders are apt to provide gentle abrasion, while liquids can cling above and below the water line for longer direct contact on the toilet ring.
You can also go to your local cleaning supply shop in town and ask them too.
Some of these tips/advice I do receive from emails or website from other people.