Step 1: Pour Coke on the tile line using a squirty top sports bottle and let it sit for about a minute. Step 2: Give it a quick scrub with a grout brush or toothbrush (the Coke will get dirty from all the muck coming up from the grout). Step 3: Wipe up the Coke with a paper towel or rag. Squeal with excitement over how much difference it made (optional). Step 4: Give the area a quick mop (I just used my Swiffer Wet Jet). The next step will be applying a sealer.