With all of the different surface/finishes on granite, it is hard to know how to clean, what needs to be resealed, etc. I've been told to never use ammonia on marble, but it is hard to know what is in some cleaners. What is safe to use on marble showers and floors? Also, regarding poly coated hardwood floors, there is conflicting info on how to clean. We had new floors installed in our last house, and the installer said to use white vinegar and water to clean. I've read in multiple places that white vinegar should NOT be used on poly coated wood floors because it will just dull the surface. The installer says to never use any of the steam cleaners on the hardwood, but there are a million of them on the market, and they claim to be safe and sanitary to use on hardwood. What's the truth? Thanks for any help in answering these basic questions