The polishing process will have you cleaning the floor first.
Cleaning and sealing only will not give a polish to the dull or scratched floor and in many cases by removing the built up layer of skin oils, dog hair oil and mop water residues will cause a dulling effect in the clients point of view. When in reality you are just restoring it to like new.
You may need to open a closet or lift a rug or piece of furniture to prove this point.