Steam cleaner won't touch the ingrained dirt, I'm afraid. Scrubbing brush, hot soapy water, and a paste of bio washing powder & bicarbonate sounds about right. As a PP said- a thick paste of bicarbonate soda, then spray on white vinegar and scrub the grout with a nail brush. Clean with water and it'll look great!
If you prefer cleaning grout with a DIY mixture, make a paste of 3/4-cup baking soda, 1/4-cup hydrogen peroxide and 1 tablespoon of mild dish soap. Apply the paste to the grout with a grout brush and scrub the grout.
Use a non-abrasive cloth and hot water for this process. Create a homemade grout cleaning solution using baking soda, hydrogen peroxide, and dishwashing soap solution. Apply a substantial amount of your homemade cleaning solution to your dingy grouts. Let it sit for 5 to 10 minutes.
Clean's best way to clean grout is with the Mr. Clean Magic Eraser Bath with Gain Original Scent. Bursting with the fresh scent of Febreze® Meadows & Rain, it's powerful enough to knock out even the most-stubborn buildup on grout throughout your bathroom.
Many toilet cleaners contain sodium hydroxide and sodium hypochlorite. These two ingredients help to remove stains and grime on porcelain or tile surfaces as well as grout. Though they can be toxic in large amounts, they do work to effectively clean grout.
One traditional way to clean grout lines is using full-strength household chlorine bleach. Ordinary household chlorine bleach is an effective way to clean grout, but because you are using it at full strength, caution is required when using it.
Mix one tablespoon of bleach with two cups of water and pour it into a plastic spray bottle. Next, spray the solution on the shower walls in other areas where the black grout is present. Let it sit for about 10 to 30 minutes, and then use a scrubber brush to clean the area. You may need to repeat this once or twice.
Start by decanting a 1:1 solution of water and vinegar into a spray bottle. Spritz all over the area, aiming for the grout and any problem spots. Let it sit for 5 minutes before scrubbing in a circular motion with a grout brush or an old toothbrush. Is your grout clean now?
Grout cleaner with Dawn Dish Soap and vinegar
Dawn has excellent cleaning properties of its own . Mix the vinegar and dish soap in a spray bottle 50/50 and spray it on the grout and let it sit for a few minutes. What is this? Scrub the grout lines with a small brush and then rinse clean.
Did you know that toothpaste makes an effective tile grout cleaner? Dab a small amount of some white or no gel onto the grout. Rub with a toothbrush. When finished, rinse a cloth with liquid soap and water and wipe clean.
Use dish soap: Combine hot water and dish soap to create a mild cleaning solution. Scrubbing with the soap mixture should wash away dirt and grime without a problem. Create a baking soda paste: Mix water and baking soda into a paste, and apply it to the grout lines.
Q: What do professionals use to clean grout? A: whether you believe it or not, most professionals use a solution of white vinegar and water with a 1:1 ratio. This solution is often more effective than dedicated Ph-neutral grout cleaners.
How do you clean grout naturally? Mix a thin paste of hydrogen peroxide and baking soda, apply it to the grout, wait 10 minutes then scrub with a toothbrush, wiped clean with a damp cloth. Baking soda is mildly abrasive so it helps remove the dirt that is stuck in the porous grout surfaces without causing any damage.
Pour vinegar along the edges of the grout. Don't do too much at once or the floor will be really wet and more difficult to work on. Pour the mixture on top of the vinegar along the grout lines. Scrub the grout lines with a stiff scrub brush.
One of the most common causes for discolored grout is dirty mop water. Rather than cleaning the tile, mop water spreads the dirt from the tile into the grout. Since the grout is the lowest part of the floor, the dirt and grime from the mop water settles into the grout.
Grout turning white can be caused by efflorescence which is the calcium from the water and the underlying concrete or mortar migrating up through the porous cementitious grout. Excessive efflorescence is considered a symptom of an excessive moisture problem.
Mold can be responsible for black grout. In areas where there is moisture or high humidity, mold can develop. Though it can appear on kitchen backsplashes, it is most commonly found on bathroom floors and shower tiles. To avoid health risks, as quickly as possible, mold should be removed.
Excess Water During Grouting
If too much water is used during the wiping up and cleaning up phase of grouting, the extra water will dilute the concrete-to-colored-pigment ratio. Once the grout begins to dry, it will have more concrete than color, which means gray will be the prominent color.
Fortunately, there is a straightforward and relatively easy process to restore grout to its original color. Simply by using a grout degreaser, along with a stiff brush, you can remove heavily ingrained grease and scum stains which are affecting the color of the grout.