I just bought a nice little old house (build in the '20-'30s)with dark stained hardwood thru 4 rooms. This next summer I will be having them refinished, in the meantime, I would like to clean them up (dusty, a little dull). They are in really good condition but what can I use to clean them? How can I tell if they are sealed or if water (or the type of cleaners that contain small amounts of polyurethane) will ruin them? I did try a damp sponge in a corner and the (plain)water seemed to bead a little and it didn't seem to immediately soak into the wood. If they may be the type that can't be cleaned using water what can I use to shine them up a little while I wait till spring? Thanks for any tips.