My wife and I are looking at buying a 10-year old house with 4″ x 4″ light colored ceramic tile on the master bath floor and in the shower.  She’s talking seriously about ripping it out and replacing it with a darker color 8 x 8 or 12 x 12 with a dark grout to minimize the cleaning issues.  The current tile jobs looks good and she’s content to keep it if we can put some sort of sealant on it to prevent the grout from being so hard to clean.  Is there such a product out there and is it any good?