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.
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).