Hard wood floor cleanin'

I will add I once did a floor that would not come clean with "normal" cleaning. There was a small chimney fire in the house, it didn't burn anything down but left a black soot film
I came in with some "special" cleaners and buffed and cleaned them, but to use this stuff, you need to go back and put new finish on the floor. It's not something you'll want to do too often but if it's super bad and could use refinishing anyway, that may be something to think about.

I probably should have mentioned in my post above that the floors in my (rental) house haven't been refinished in decades, so there's no current finish to damage My mom uses the Orange Glo on her new hardwood, though - it was recommended by the installer. *shrug*

What finish is on the wood? If it is a wax finish, you can't get water on it. You'll have to strip it down to the wood and re-wax it.