Tile and grout cleaning and whitening works if the tile hasn’t been etched or scratched. Tile and grout in bathroom article. Floor grout cleaning and sealer
For tile and grout cleaning, start with T.S.P. (trisodium phosphate) mixed in a very strong solution with warm water. Add 1/2-pound T.S.P. to a gallon of water. If there is any mold on the tile surface, add 1/3 cup of cleaning bleach. Remember concentrated T.S.P. can be harmful to the skin. Heed label warnings and wear protective clothing. Bluette gloves and goggles are a nice start. Have rinse water available in case you get any T.S.P. on yourself. Apply the mixture over the area using a long-handled tool like a sponge mop, or a brush with a long handle. The brush doesn’t need to be very stiff. It only has to apply the product on the surface.
Let it work for about ten minutes, then reapply it using a little elbow grease this time. Scrub, don’t rinse, and repeat the procedure if necessary. Sometimes this process needs to be repeated three times for the best results.
If after three coats of strong T.S.P. and scrubbing, the tile still isn’t up to par, there are still several alternatives.
Tile and grout whitening for rust stains use a paste of bleaching cleanser and water. (Zud cleanser contains oxalic acid) Apply the mixture over the stained area; keep it damp for up to an hour. The oxalic acid in the Zud should bleach out most stains. The more desperate can even try pure oxalic acid commonly found as wood bleach.
Acidic surface cleaners, like C.L.R., or IRON OUT are often useful to remove a dull sheen. These cleaners use mild acid to dissolve calcium deposits from the tile.
As for grout cleaning, TILE GUARD makes a tile grout coating that goes on like a latex paint. It comes with an applicator similar to a liquid shoe polish. Let it dry for four hours and buff the residue off the tile with a damp brush or sponge. Some areas may require a second application to cover some discolored areas.