Toilet stains are hard to remove with the eco friendly green help like baking soda and salt and hot water. But here is a simple method from Caroline Harris in her book MS Harris’s Book of Green Household Management. It will help you to get rid of stains and limescale where the bacteria collects.
Every couple of months pop two tablespoons of citric acid – available from pharmacies or online in the toilet pan. You can substitute half a cup of vinegar but it does not work as well as citric acid, she tells us. Leave it overnight or even while you are away. Much of the limescale will simply float off, while the toilet brush, a sturdy, wiry one will scrape off the rest!