look into VAPOR machines instead of STEAM, Heating element temps are higher creating less water residue to wipe up, more sanitary, and the vapors pull Dirt to the surface, not water, and i found that vapor cleaners are the best grout cleaners in the world. The commercial machine I bought was called EURO STEAM VAPOR cleaners and the results are amazing. A little elbow grease and no chemicals create the most amazing results you've ever seen.