How to: remove grout haze from tile

I will have to apologize in advance for this will not be my prettiest post. As new homeowners this summer we attempted tiling for the first time; everything was working in our favor, the tile was cheap, the floor had been leveled, the new tiled floor was going to be gorgeous. We finished in a weekend and were eager to move on (so we could use the kitchen, of course!). I didn't stress at first that my tiles looked dirty because I felt I would clean the floor once the reno was complete:

 

So months went  by (yes, months). Small kids and the business got in the way and we moved on to tackle the rest of the kitchen so we could cook, a necessity when living through a renovation. I attempted scrubbing the floor several times with Pine sol and Lysol with no success, and the husband assured me I would just have to tackle it with boiling hot water and a scrub brush when we had some time. I finally had enough one day, boiled the kettle and scrubbed away. Nothing.
Suggestions of vinegar did not work either, so I panicked.
The tile shop suggested a product called grout haze remover by R & D Chemical Solutions; if you can not find this there are many other similar acid based solutions out on the market. After following directions (small areas, and allowing 15 minutes each area to soak), our floor looked like this:

Not bad. My husband realized in retrospect that the project could have gone faster (and saved knees!) with larger areas and a deck brush. The stubborn spots came off easily with a little spray of concentrated solution. Now I feel my kitchen is really coming together!

I am thrilled that something worked to save my husband's hard work. Not bad for his first time tiling, don't you think?