You may think keeping a bathroom clean is an easy chore because all you have to do is wipe everything down regularly and scrub the toilet every once in a while. The fact is that bathrooms are one of the hardest rooms to keep clean because they are almost always tiled and tile grout is one of the hardest things to keep clean in bathrooms or wet rooms. Tile grout is porous and dirt, grime, mold, and mildew can all find their way deep into your grout where a wipe down will not touch it. You need more vigorous cleaning.
There are several techniques that I keep in mind when I am ready to clean tile grout. The first may sound silly, but the best way to clean grout is to not let it get dirty in the first place. If you do your grout cleaning regularly, then it will never get that dirty and the job will never be that hard. The best way to make yourself the best grout cleaner is to clean your grout often. I like to spend about five minutes every day when I am in the shower cleaning a section of the grout in my walk in shower. This is the hardest grout to keep clean because it is exposed to the most dirt, soap, and water. If you keep up the grout cleaning schedule every day, then it will never get too bad.
Another helpful hint is to use a medium bristled brush. You may think that a professional grout cleaner uses the hardest bristled brush they have available and so should you, but hard bristle brushes will actually destroy the grout rather than clean it. The medium bristles are just hard enough to help you get a good clean, but not so hard that they chew up the grout.
When you are scrubbing the grout make sure to use circular motions rather than back and forth motions over the grout lines. If you scrub straight back and forth over the lines you will be loosening dirt on the up stroke and then pushing it back into the grout on the back stroke. Circular motions allow you to scrub the dirt out and then push the dirt to the side before you go back to scrub the grout again.
One final tip is to use the least harsh cleaning solution you can to still get the job done. Grout and grout sealant can be worn away over time and harsh chemicals will speed up that process. Test different cleaners in small places that are hard to see to determine what the best grout cleaners are. Never use something harsher if something less harsh will get the job done. The integrity of your grout is not the only thing that benefits from this cautious approach. Harsh chemicals can be harmful to children or pets that crawl around on the floor as well.