Toothbrush Dirt

I have come to the conclusion that here exists a particular stain of dirt that is only cleanable using a toothbrush. Think about it. I am sure most people have had something in their life that they have tried and tried to clean but nothing worked except the toothbrush.

My experience was with the grout on the kitchen floor. I believe the original color of the grout was white. Over time it turned into this brownish-gray color. I have tried EVERYTHING to clean the grout since we bought the house. Mopping, steam cleaners, Tilex, wash cloth scrubbing, etc. Finally, I decided to try bleach and a toothbrush. At last! I found the magic combination! I am truly grateful for finding some way of cleaning the grout. I do wish toothbrushes came in a bigger size. The kitchen and dining room are quite large compared to a toothbrush.