Terra cotta is a rich, red-clay tile product. It is not fired to the high temperatures that porcelain or ceramic tiles are, which makes these tiles porous, much like natural stone. These pores can cause the tiles to trap and hold onto stains, such as salt. To remove salt stains from terra cotta, use a mild cleanser made for tile or stone and a poultice to lift the stains out of any surface pores.
Clean the terra cotta tiles with a mild tile cleanser. Pour the cleanser directly onto the stain and use a scrub brush to work it into the tile. The texture of the surface of the tile could rip a sponge or cloth, so a stiff-bristled brush is needed.
Pour warm water over the tiles to rinse and allow them to dry naturally.
Spread a tile poultice over the salt stain to help lift it out. Poultices are available in both liquid and powder and may require mixing. Follow the manufacturer's directions to mix the poultice to the correct consistency.
Cover the poultice with a piece of cling film or plastic sheeting to help it remove the salt stain. Allow the poultice to work for one hour.
Pour warm water over the poultice and use the scrub brush to remove the poultice and stain from the terra cotta. Allow the tiles to dry naturally.