So while I was waiting for Thanksgiving dinner to cook at my moms house I was determind to see if this pin actually worked. About 3 1/2 years ago my grandma had her niece tile her kitchen floor. After about a year or so the grout began to darken and it never looked clean no matter how often we cleaned it.
I got out a bowl and place
7 cups water
1/2 cup baking soda
1/3 cup ammonia (or lemon juice which is what I used)
and 1/4 cup vinegar
I mixed it up and poured it over the grout and let it set. With a scrubber I found under sink I began scrubbing away at it. You could actually see the dirty water! I was amazed.
It really does work! It is a really big work out though and worth it on special occasions. My mom wouldn't let me finish because it was Thanksgiving...so about half of her kitchen floor is clean and the other half isn't. Note the different colors in the grout in this picture?