How to clean a toilet bowl that is extremely dirty?

Has she tried white vinegar? Turn the water to the toilet off. Flush all of the water out. Pour the white vinegar in the bowl so that it covers the stains. Some people say to leave it over night, but a few hours should work (we have also used this technique to get rid of cigarette smell out of fabrics). Then turn the water to the toilet back on, let it fill back up then flush it. Hope it helps!

A Pumice stone if bleach and scrubbing doesn't work.

I wrote a tutorial on cleaning your toilet, maybe this will help you - https://chascrazycreations.com/how-to-clean-your-toilet-from-top-to-bottom/

It depends on what the staining is suspected to be. If do to iron in the water you would need a product called iron-out. If it is mineral build-up from hard water then CLR or Limeaway could help, otherwise try products made to clean toilets. Please do not mix products together. Try one and if no effect, flush well and try the next. Many products create dangerous gasses if mixed. Good luck.

Boil water and pour in the bowl to help loosen the dirt and stains. Choose your cleaner based on your best guess of what caused the stain. Magic eraser before pumice (it could scratch).

June, A google search showed that Home Depot, Lowe's and Walmart all carry the iron-out product. They all should have the CLR or Lime-away also. You may have to ask someone at the store if they have the products. Generally they should be with the cleaning products.

Try some of these: Home and Garden DIY Ideas | Hometalk

Flush the toilet and then pour a quarter cup of Borax into it. Use your toilet brush to swish it around. Next, add one to two cups of vinegar and let the mixture sit for 30 minutes. You should be able to scrub the stains away!