What is the best product to clean granite tile in a kitchen?

I have started my own cleaning business in my neighborhood. One of my clients has granite tile in her kitchen, and it is a pain to clean. I feel like water and cleaning solutions just leave streaks on the floor. I am looking for a good product to spray/pour on the floor and wipe clean. Any suggestions?

vinegar.

DO NOT USE any acid based liquid (e.g. lemon juice, orange juice, Windex, vinegar) as it will etch the granite (i.e. remove shine) PERMANENTLY! It only takes 30 mintues to etch.
Use Tilelab. To avoid dullness, wash the floor with product, then rinse with plain water. Report It

try using baking soda diluted in water(lukewarm water to be specific

I like several cleaners for my granite. Modern makes a cleaner that is all natural and non-toxic, but tends to smear grease, too, particularly on honed or shiny stone. TileLab makes an excellent cleaner and protector which does a good job on the grease, doesn't smear and leaves a protective shine that resists staining and water rings. Counter top magic works well too and is easier to find and less expensive. TileLab is mostly sold at home improvement stores and Counter top magic (for stone) can be found at most big discounters, grocery stores and even some of the drug stores, like Longs.