QUESTIONI have 15 yr old 13" square porcelain tile that looks like stone, has pits in it as the design and is glazed. Over the years the morter has become darker or stained in some areas as well as the pits getting darker. Can I white wash it somehow to bring it back to its new like state so it's lighter and more consistent again? Not a rectified tile so grout lines are bigger, it has the rough edges and is beige in color.
ANSWERANSWER - Since you have a glazed ceramic tile it should come clean unless it has worn from abrasion. Glazed ceramic tiles don't normally fade, but some of the softer glazes might to some degree.
I would get a neutral based detergent to add to water and soak the tile for about 10 minutes. Then get a bristle scrub brush on an extended handle and scrub the tile making sure it isn't too abrasive to scratch it. Then get a wet vacuum to pick up the dirty water. Then apply the detergent again, scrub, and vacuum. Then rinse the floor with clean water and vacuum.
You can also consider using a power washer after scrubbing as long as it doesn't harm the tile.
If the discoloration or stains are oil based or hydro carbon based there are some strippers for removing tile sealers that might work.
Whatever you do, always test a small out of the way area first to make sure you get satisfactory results before proceeding treating the entire tile floor.