Brick provides a lovely accent to any home or office. Like any interior surface, brick work needs to be cleaned regularly to look its best the rough finish of the brick and the cement grouting makes it easy for dust and dirt to adhere to the surface. While regular dusting is essential, sooner or later stains will develop which will need a little special attention to remove them. There are various ways of cleaning bricks and what follows are to of the least aggressive methods. If they do not work for you, rather than experiment with more extreme methods yourself and perhaps do more harm than good, it is preferable to get the help of a home cleaning agency.
Take a cake of dish soap (the grease and oil removing kind) and cut in half (the size will depend on the brick area to be cleaned). Place it in a bowl and add an equal quantity of ordinary table salt. Using just a little water mix the soap and salt into a thick paste. Using a clean rag spread the paste evenly over the brick surface. The thickness of the paste on the brick is not important as long as the entire surface is covered evenly.
Using a hard scrub brush, rub the paste into the brickwork and allow it to remain there for about 10 minutes before rinsing off with a clean cloth dipped in warm water. You should see a noticeable difference in the finish of the bricks.
But if this does not yield the results you want, you can try-
In a clean bucket mix warm (not hot) water and boric acid in the proportion of one tablespoon of the acid to one gallon of water. Put on rubber gloves and goggles you are going to be scrubbing and some of the mixture could spray back into your eyes. Take a hard scrub brush, dip it in the solution and vigorously scrub the brick surface. Allow the solution to rest on the bricks for a minute or two and then rinse it away with a rag dipped in warm water.
If this still does not give you the results you want, contact a professional office cleaning agency to do the job. Using strong chemicals on your own can be dangerous not only to you but may damage floors, walls and furniture. Do not try more aggressive cleaning methods unless you are sure of what you are doing.