It is simply for aesthetics. In other words, it is to make it look pretty, so if the job requires it, I would use it. Wax and shine is also optional. You don’t have to use. The tile and grout treater is a less of a shine but looks nice regardless. Wax and shine is just a bonus, and can be offered to raise the amount of money you will make, for example; basic tile and grout clean from $.40 to $.65 per square foot. With wax and shine, charge more at around$.65 to .95 psf. You pricing structure is up to you. Good luck and God Bless.
Mike Nowlin