What's the best way to remove grout from the tiny pores in backsplash tiles? I tried grout haze remover and distilled white vinegar without much success. I am not sure if there is a certain amount of time I should leave the vinegar on the tiles before wiping off with water. Any suggestions would be appreciated.
Depending on the type of tile, muriatic acid might do it. Recommended to test on an inconspicuous area. Follow instructions and proper safety procedures. A less dangerous and more tedious way would be to use a dental pick to remove it.
Vinegar has a hard enough time removing just haze. Actual grout; good luck.
Tiles with holes in them are supposed to be filled with grout, and are usually floors, not backslashes. You should have chosen a grout color better suited to porous tile; which is always an option, especially if you want darker (which is always the way to go, imo).