I just mop with hot water. Porcelain isn't a delicate material.

A good vacuum will keep stuff from accumulating in the indentations.

Hot water is good....just use a standard string mop....NOT a "sponge-type." It only moves the dirt around. Any cleaner you use should be a "Neutral PH Cleaner" so as not to wash out the grout colour.

You can also shop vac up the dirty water. My tile guy recommended doing that twice a year for a deep clean of the grout. I never have though since I have epoxy grout. I know you're not supposed to use bleach on sanded grout, which is a common mistake.

thanks everyone! keep the suggestions coming! For now I will stick with the hot water unless someone has a cleaner suggestion. :)

I have porcelain. A tile expert recommended Super Shine All by Hillyard. I like it alot. I had tried the shark steamer and a wet Swiffer but was not satisfied with the results. The label for SSA recommends using cold water with it. I have a SH mop. What I do is go over the area with a microfiber dust mophead broom and/or vaccuum as needed, go over once with plain warm water, and then again with the SSA, with excellent results.

I use Young Living Thieves cleaner on all of my floors including my porcelain. I use a "swiffer" type mop. It's not a delicate surface, but just like any floor it does get dirty.