One of my biggest projects each year is cleaning grout. All of mine is white so it shows dirt fairly easy.
I have used different solutions that I purchased to clean my grout, but was never totally satisfied with the results.
I found this recipe for a homemade mixture on the internet and it is amazing!! (http://gatheredinthekitchen.com)
* 7 cups water
* 1/2 cup baking soda
* 1/3 cup lemon juice
* 1/4 cup vinegar ( I use white)
Mix all ingredients in a bowl or bucket. Apply to grout with a toothbrush. Scrub. Wipe up excess with a dry cloth. I actually let it set about an hour and then scrub the floor with clear water. When it dries it continues to become more white.
I also have this in 2 bathrooms. This solution even cleans hairspray off the tile in the bathroom.
As I stated, the commercial products that I have previously purchased did not give me the results I was looking for. This homemade solution seems to be mild on the tile flooring and cleans so well. As with any product, please test it on a small area first.