The tiles they are generally quite resistant to stains but some such as from clay pots, varnish and even rust can leave permanent marks.
There are many ways to remove these stains using everything from baking soda to hydrogen peroxide, but some methods are more effective than others.
Remember to test the stain remover first on an inconspicuous spot to see if the tiles react negatively to the substances in the solution.
Dab the stain with hydrogen peroxide. This is a powerful cleaning chemical, even when diluted, so use only the amount required to clean the stain. It is slightly corrosive, so wash the surface thoroughly with tap water once the stain is gone.
If your stain is particularly difficult to remove, spread a cloth soaked in hydrogen peroxide over it. Leave it on for 1-2 hours. Then remove the cloth and rub the stain.
Hydrogen peroxide is especially effective for cleaning coffee stains, nail polish and blood on tiles.
Pour a capful of bleach into a bucket of cold water (3.8 L) and stir. Then use a white cloth to dab and rub the stain. If the solution is not strong enough, add another capful of bleach.
Scrub the stain with a sponge and rinse with plenty of water. To use another cleaner you should let the area dry for a few hours.
Wet the stain lightly with water, then sprinkle enough cleaning powder to cover it completely. Mix the paste and let it act for a few minutes. You may need to scrub the stain with an old toothbrush. Once the stain is gone, clean the surface with a cloth and rinse the tiles with water.
With information from wikihow.com