When it comes time to clean the grout in your bathroom or kitchen one of questions you might need to answer is what kind of cleaner you should use. The rule that I always stick to is to use the least harsh cleaner that will get the job done. Of course, it is hard to know what that option is without going through all of the chemicals until you find one that works. Therefore, that is just what you should do. Start with the simplest cleaner, steam and go up in harshness from there.
Shortly after I moved into my home, I had to do some heavy duty cleaning on my bathroom tile grout. I tried all of the gentle cleaners but they were not doing the trick. I had to use an industrial strength cleaner in combination with some professional grout cleaning machines. Once I got my grout clean, I was able to maintain it with a simple vinegar and water solution.
Why should you use vinegar for grout? Some people call vinegar a miracle cleaner because it can be used in a wide variety of situations. Vinegar is a weak form of acetic acid and its acidic properties are part of what makes it such a good cleaner. When you use vinegar on grout, the acid dissolves the dirt particles and mildews, and then a water rinse carries them away. You need to be careful though, because the vinegar could dissolve the grout. If the grout has been sealed, that will help, but you need to test your vinegar solution on a small inconspicuous area before using it on the whole floor.
When you use a vinegar solution to clean grout you need to make sure you allow enough time for the vinegar to work. Most likely you will let the solution sit on the grout for anywhere from two to ten minutes. The longer you let the vinegar sit the more dissolving action will occur. However, remember not to let it sit too long.