L.A.
I used to work for a flooring contractor and can tell you that Bona flooring cleaner is recommended by most flooring manufacturers. It is made specifically for wood floors. You can purchase it at OSH and most hardware stores and from flooring contractors who have retail space.
NEVER use Murphy's Oil Soap or steam to clean a hardwood floor. No reliable flooring contractor would advise it. Steam can cause the wood to swell and warp. MOS leaves a residue behind that ruins the finish in such a way that when your floor needs "refreshing", you'll be paying for a complete refinish job, not just a "screen & coat". A complete refinish of a floor requires sanding down to bare wood and applying multiple coats of finish. A screen & coat is a light sand and application of a single coat to refresh the finish, which costs about half as much (or less) as a complete refinish. If you're really in doubt and want to make certain you do the right thing for your floors, contact a local flooring contractor and get a recommendation. Bona does a wonderful job of cleaning and enhancing the finish on your floors. It's really the best way to go.