After weeks of scrubbing tile grout with bleach-based sprays and listening to that squeaky clean sound, I finally watched a video about using a steamer. It made the yellowed lines between my shower tiles look almost new, though I did have to scrape a few stubborn spots with a thin brush. The water that came out was disgusting. Now I just need to reseal the grout so it stays clean longer, but honestly, the steam method was way less elbow grease than I expected. grout cleaning