DuPont Mold & Mildew Stain Remover for Natural Stone

This product worked better than expected. I had some stubborn mildew stains in the stone floor of my shower. I had treated the stains repeated over the past few years with grocery store mildew products like Tile-X. Those products lightened the stains a little, but they were still very noticeable. When I first tried this product, I didn't think it was working better than Tile-X. But I let it sit for most of the day, and eventually it eliminated the deep set mildew stains in the stone. I don't know whether this product has different chemicals in it, or whether it's just thicker and therefore able to stay and work on the stains better. In either case, after one day (and repeated applications), the stains that have resisted me for years are finally gone. The product has a faint bleach smell, so I'm assuming that's the working ingredient. Very easy to use. Just spray, let it set, then rinse. If your stone is sealed, you'll probably have to use a scrubbing product first to remove the sealant layer, then apply this stain remover, then rinse, clean with an everyday stone cleaning product (like Granite Gold Everyday), then reseal.

I have a stone shower in a bathroom that lacks proper ventilation so there is a constant battle with mold. I have tried dozens of products over the years and nothing has worked. I just used this for the first time and it removed the stubborn mold the first pass! I used a nylon brush to scrub the grout and corners so it did involve some elbow grease but I am thrilled how effective this product is. Beware, the smell is strong so open a window and have a fan running. I will certainly be buying more of this!

We live in Southwest Florida where the combination of high heat and humidity makes it ideal for growing mold and mildew. Getting it off natural (unsealed) stone is not as easy as you might think. Most of the products I researched will damage natural stone because of the Ph. People tend to forget that natural stone is porous and will absorb liquids -- and therefore show stains. Trying to use regular grout cleaner on marble will result in the marble edges touching the grout looking like someone buffed the sheen off it. Not good! After looking, researching, and trying several grout cleaning products, I finally found this DuPont Stonetech Mold & Mildew Stain Remover. It is a bit pricey but after several failures I was willing to pay a little more to effectively solve my problem. Our shower stall is composed of travertine walls and floors. Since it is in the corner of our master bath and has almost a floor-to-ceiling glass door, there isn't enough air circulation in it to prevent the formation of mold and mildew. Mold and mildew removal is pretty easy. Simply spray the mixture on your grout lines, wait a few minutes, and then scrub with a non-abrasive sponge or an old toothbrush. It doesn't take a lot of effort although stubborn stains will require a second treatment. The other tool that I've found to be indispensable in cleaning the shower is to use a clothes steamer. Anything that resists two treatments with the DuPont Stonetech product will easily be eliminated by using your clothes steamer. Just hold the steam head very close to the grout and the mold/mildew will disappear. And if there is still evidence of mold/mildew, try using a fine tipped scratch pen/sanding pen. Amazon sells the KTI-70550 for about $7.00. This essentially allows you to sand the offending mold/mildew off the grout while staying on the grout line and avoiding the marble edges. While using this cleaner, make sure that you have proper ventilation and use a mask to avoid breathing in the fumes. That strong smell that reminds you of bleach is sodium hypochlorite -- which is actually BLEACH. So take care to protect yourself and not damage your lungs. After using your clothes steamer for awhile you may decide that you get acceptable results (depending on how bad the mold/mildew is) just by using the steamer and avoiding the fumes.

Okay, I love this cleaner. It cleans my stone tile way better than anything I have tried. However, almost passed out using it. I’ve cleaned with tons of products and have never had that issue. Maybe I used too much? Definitely have a fan circulating air and open a window!

This stuff worked so well I actually wanted to cry. We have a full marble shower and it stays warm and wet in there constantly because it’s used a lot and the door can’t be held open. It was impossible to remove the black in the shelves and corners and grout and some of the scrub stuff can damage the stone. I sprayed this and let it sit and everything washes away. It’s amazing. I wish I had a before picture but I didn’t take one because I didn’t actually expect it to work as well as it did. As for the smell it’s kind like a chlorine. I opened the bathroom window and ran the fan for the day and made sure to rinse everything well. I’m ready to buy another bottle and am so happy I found this. It also removed some stubborn stains on the glass door.

This stuff is amazing! I moved into a new home where the entire shower is marble- both walls and floor. The house had been empty awhile and so mold and mildew was creeping in, especially the orange type in all the grout on the floor. I could not use any of my normal cleaners on the marble and the 1 marble cleaner I had did nothing for the mildew. But this stuff worked wonders. It helped a but just by spraying it on, adding a good scrub and it was nothing short of amazing. The grout is clean is light gray again and all the marble is shining.

No improvement in flooring.AT all

I have applied this quite a few times. Not as effective as I had hoped. Directions don't say how long to leave spray on tile before removing. Although some mold has been removed, I think I will have to reapply, reapply, reapply. Stonetech is a good company so I had high hopes it would be effective right away.