Don't try passing off mopping the tiles on your floor as grout cleaning. Perhaps you'll be able to clean the tiles; or if you're particularly handy with a mop, even make the tiles look something special. You will not, however, even remotely touch the grout in between. This may not seem like a big deal to you, but picture this: Have you ever been tired just moving from your office cubicle to the bathroom? This is because of the mold accumulating in dirty grout.

So have that grout cleaned, even if you are fond of the blackness of the grout contrasting the brightness of the tiles. If this is the effect that you are after, then have your grout dyed with a darker shade at the soonest time possible. Maintain a healthy environment and have it cleaned now.

Are you asking me how to clean your grout? That's a start, but we still have a long way to go, my friend. There are numerous products marketed out there at outrageous prices, all of them claiming to be the answer to your grout problem. Few even work. If you want to go this path, I suggest you prepare yourself for a long road of disappointment; you will, however, find a brand that fits your floor eventually.

If equipment is the issue, then there are also a lot of items in the market for your needs. There are a bunch of electronic scrubbers that you can buy, although I would advise you to research more on the topic, because I haven't. To me, if you want it done by machine anyway, let it be handled by someone who won't accidentally misuse it and end up destroying your floor.

My advice for you? Instead of buying mechanical equipment, hire professional grout cleaners instead. I guarantee that the machinery they buy will be better than what you are eyeing. Using these, they will get your grout as clean as the day you got them.