Limescale is an unsightly white substance that can be found inside kettles and toilets, and on taps and shower heads.

The unpleasant staining is caused by the water inside the toilet bowl evaporating and leaving behind the minerals, calcium, and magnesium.

Limescale often turns toilet bowls brown, black, or green and can make them look especially grubby, even if they’re not.

Most people resort to using chemicals when removing toilet limescale. However, these can be pungent and potentially harmful if they are not used correctly.

The most popular natural method is vinegar and baking soda, however, some fans of cleaning sensation Mrs Hinch claim the hack isn’t that effective.

Benjamin White posted on the group, ‘Mrs Hinch Cleaning Tips’, “Have very bad limescale in toilet that’s built up. Any tips? Bleach and vinegars aren’t very effective thus far.”

Hellen Anderson also posted: “Limescale on the bottom of the toilet bowl – HELP. So far, I have tried vinegar and baking soda, Viakal and lots of scrubbing. Nothing is working!”

Instead of using vinegar and baking soda, some Mrs Hinch fans suggested using citric acid to remove stubborn toilet limescale.

The solution was suggested when cleaner Pamela Maloret posted a photo of one of her clients’ toilets which was covered in brown limescale.

She added: “I’ve used Harpic tablets in it twice for two hours but it hasn’t removed any of the limescale. What else can I use please? Need help. Thanks in advance.”

The post received more than 400 comments, with citric acid being one of the main natural suggestions.

Chell Childs said: “Citric acid was the only thing that worked for us and we had tried lots of different things.”

Gez Bardon WasKelly wrote: “Nancy Birtwhistle on instagram makes a brilliant cleaner made from citric acid, called pure magic and it really is, removed the limescale from my toilet straight away.”

Millie Kieran posted: “My new best friend. Citric Acid overnight. Brilliant.”

Julie Day replied: “Boiling water and citric acid. Citric acid is absolutely amazing for limescale. Leave it in the toilet bowl for a few hours.”

Citric acid can be found in citrus fruits such as lemons, limes, oranges and grapefruits.

To use citric acid to remove toilet limescale, put two tablespoons of the substance into the toilet and leave it to work for around 20 minutes. Scrub it with a brush and then flush the toilet.