Black Diamond Ultimate Grout Cleaner: Best Cleaner for Tile,Ceramic,Porcelain, Marble Acid-Free Safe Deep Cleaner & Stain Remover for Even The Dirtiest Grout. (1-Quart/1-Brush)

Used this on my marble shower grout lines and it cleaned them easily. I sprayed it on the entire surface of the shower, let it sit for a few minutes then scrubbed the grout clean without issue. This is a great product to use regularly. My grout was never extremely dirty so I can’t speak on its effectivess on neglected surfaces.

I'm not sure the grout in our bathroom has been cleaned since the floor was installed 20 years ago. Sure, the floor has been mopped often, but nothing for the grout in particular. So I really didn't expect to get the grout looking new, I was just hoping for better.The grout now looks pretty much new.After a bit of trial-and-error, here's the process I used.1) Buy a battery powered scrub brush. These look like an electric toothbrush on steroids. I bought one by Rubbermaid, but there are others that are probably equally good. I can't imagine using this with a hand scrub brush.2) Spray this on the grout, let sit for 5-10 minutes. Not any longer, or it will dry too much.3) Go over the grout with your battery-powered scrub brush. Multiple times. Over a 2-3 minute period. This part is critical, the first cleaning got a lot of dirt up, but with repeated brushing it got *really* clean.4) Rinse a couple times.5) Wait a couple hours for the grout to fully dry, and admire your handiwork!For me, a couple spots needed a second application, but the floor looks so much better now. Highly recommended.

My rented house kitchen tile grout was filthy and probably never cleaned. I started by trying all the at home methods I came across online that promised to work, but of course didn’t. This stuff though, I was surprised to find really did the job and turned my almost black grout in spots back to beige. Did it require scrubbing? Yes. Did it take more than once? Yes, for the worst spots. Did it make my kitchen floor look cleaned? Absolutely! Another positive is that it has a relatively pleasant smell and the brush is good and held up for hours of cleaning. The only downside is that it’s on the pricey side for some floor cleaner and I used quite a bit through my whole kitchen and dining room.

I tried to clean my bathroom tiles and the grout. It did nothing to clean the grout. It is still the same as it was before. I’m going to try a standing grout brush to see if that makes a difference. But as of now, I’m down $20 something dollars and a very sore hand and wrist from scrubbing so hard. I gave it three stars because I like the smell. Other than that, didn’t work.

Wow! I have been cleaning my tile and grout for 6 months in a house we bought. I’ve tried special mopping solution. I got a tile scrubber and used the baking soda hydrogen peroxide hack among others to no avail. I sprayed this diamond grout cleaner along the grout and in 3 minutes scrubbed it with the included brush, wiped it up with a wet paper towel and it was like new!!!!!! Finally a product that did what it said! My grout lines were pale grey but almost black along the well walked areas. I assumed it was oil from peoples bare feet mostly making them so ugly. Yay! Clean as a whistle now! I had to be wary of harsh products because my tiles are marble.

Works really well my grout floors. Easy to use and cleans up well.

Amazing results! Had pink mold in the shower and kitchen counter - worked great after one application. Used again a month later and cleared up more! The small brush definitely helps, but it is a bit of a workout 😅 It seemed a bit expensive at first, but worth it

The product itself works okay, not perfect but adequate with scrubbing. The biggest issue I had is the bottle coming unscrewed while using the product and then falling and making a mess all over.