Not all areas of your house will have wooden floorboards. Most people prefer to have their kitchen and bathroom floors tiled so that they get less dirty and are easier to maintain. Tiles add a wonderful elegance to your house but they also pose the unfortunate problem of grout cleaning. Grout is the concrete-like substance that is used to fill in the space between the tiles and they are notorious for being very difficult to clean. Most commercial grout cleaners used by the cleaning agencies are made of corrosive chemicals. A common household alternative is using chlorine bleach or vinegar and baking powder, but they will not work on deep-set grime. The only other fairly non-toxic domestic cleaning alternative is using some oxygen bleach such as hydrogen peroxide, sodium percarbonate and sodium perborate. Hydrogen peroxide has far less cleaning capacity than percarbonate or perborate salts, as it is sold in highly dilute conditions. Alternatively, you can also use commercial oxygen bleach-based products that are used by professional cleaning companies.How to clean tile grout?• Follow the directions on the label and mix the oxygen bleach powder in some amount of water, depending on how much area you need to clean. The powder will not dissolve readily, so you might need to stir it until most of it is in solution.• You can either pour the solution over an area of the floor and use a brush to spread it over a large area or, for more directed action, use a dropper to apply it directly to the grout. It would be best to start at the end furthest from the door and work along the length or breadth in sections that are no larger than an arm’s length.• Let the solution sit undisturbed on the grout for a few minutes for the chemical reaction to allow the oxygen to lift the stains. You will notice that there might be bubbles or foaming during this period. The longer you let it sit, the more dirt it will remove. • Use an old toothbrush or a grout brush with stiff bristles to scrub the stains loose. Wipe it away with a rag before the dirt can settle back. Rinse the rag frequently if it gets dirty. After you are done with scrubbing the floor and wiping away the bleach, give the floor a good mop with clean water to rinse.• Wet grout will appear a bit darker so wait for it to dry before you judge the finished result. If you think your floor could be a little more whiter, repeat the procedure again. If you are not sure what the original colour of the grout is, look under less-traffic areas such as under the radiator or behind the toilet to see what it could have looked like originally. If your floor has been in a prolonged state of neglect, chances are that oxygen bleaching would take a long time to remove all the stains. In such a case, you might want to consider professional cleaners for a one-off job.Cleaning grout is a very tedious process and a bit rough on your back and knees. So if you want to avoid having to do it regularly, you might want to use a grout sealer or protector to keep the grout from accumulating dirt. However, be advised that not all products available in the market are environment friendly and safe for you to use. So make sure you know what you are buying.