Before on left.
After on right.
So much better.
People say that vinegar is the best clearer for grout. They seem to be correct. :) The bathroom floors look way better.
Also, I will never never never put tile into a bathroom (or any floors in my house). It is hard to clean, cold, hard, and doesn't hide dirt well. But since I have it, I will take care of it. It does last a long time.