Tile is highly resistant to staining, but it's still important to clean spills right away. Avoid letting acidic substances linger on grout lines. Juices, coffee, vinegar, wine, soft drinks & certain condiments can cause dull areas or marks. You should also never use bleach, ammonia, or abrasive cleaning solutions, as these can break down the sealant and make your tile even more prone to stains. Generally, a damp cloth with a mild detergent is all that you need to wipe up liquid spills.