when I had my oak floors installed, I was told to use white vinegar and water, once every 6 mos. is good. that person didn't have 2 dogs and an assortment of people in the house constantly.
I was also suffering dearly with gorgeous tile with disgusting grout (poor choice n my part- light beige). I researched and bought a Hoover hard floor cleaner. It cleans and suctions up the water. Works great on the tile and hard wood. The tile is slowly brightening up too. I love it!!!
I just bought a HAAN steam mop- not for the floors but because it came with a pad to sanitize carpets. Going to try that out today.