Even the same day after damp mopping with a wood-floor cleaner, if I have to wipe up a spill in the kitchen, the paper towel always looks so dirty! Am I not getting my floors clean, or is this just normal?
I don't think it's clean unless you mop it with a cleaner then rinse with a clean mop. It is my experience that you are just spreading it around. An example is if you go in a restaurant and the floor is sticky. It's a pop spill and someone just used a wet mop to clean it up. They don't rinse it with a clean mop. The pop is still there they just went through the motions and spread it around.
I use soap and water on 99% of the things I clean, it's cheaper and does a better job.
This is just an opinion, but I think it is normal for so-called wood floor cleaners to leave some sort of residue, since the cleaner is not rinsed away.
I think it is true with any floor or any cleaner. It's only spread around until you go over it with a clean mop.