Black Diamond's Ultimate Grout Cleaner: Acid-free and Effective

Grout is a sneaky defector, changing from a light grey to a deep brown so gradually that you often won’t notice until it’s completely taken over your tiles. Once you’ve spotted it, though, you can bet you won’t forget it. Luckily, the cleaning process isn’t as daunting as you may assume. There’s a reason your regular ol’ soap and sponge method has yet to work—there are certain cleaners specifically formulated to target grout stains. We tested a few of them—judging effectiveness, safety risks, and scent—to find the best out there. Keep reading to see how Black Diamond performed in our bathroom.

Performance: Worked like a charm

Before you get to work, the only additional item you’ll need is a grout brush. Already have one? Great! You’re good to go. So first things first, spray the product onto all grout in desperate need of buffing. The directions advise leaving the solution for one to three minutes, so naturally, we let it stew on our bathroom walls for five. Disclaimer: We were facing some pretty well-established shower grime that hadn’t been properly tended to in months, but even if you have a normal level of sludge, a few extra minutes can help cut through tough buildup.

After the formula had settled for several minutes, we took our grout brush to the tiles and were instantly filled with satisfaction as brown and red dirt separated from the grout, running down the shower walls in defeat. Of course, some areas were more stubborn than others, but it was nothing a little extra muscle couldn’t solve. The dirt and mildew scrubbed away relatively quickly, and when we gave it a final once over with a soft sponge and a few sprays from the shower head, the difference was astounding. The whole cleaning process took about 30 minutes. Black Diamond worked better than anticipated, and we might even agree with its self-proclaimed classification as the “ultimate” cleaner.

Ingredients: Gentle but effective

It’s worth noting that this grout cleaner—unlike most others—is acid-free. The upside of an acid-free formula is that it’s gentler on skin and also mild enough to use on marble. On the flip side, however, Black Diamond isn’t robust enough to tackle calcium or water spots.

Safety: Take necessary precautions

The directions advise to wear eye and hand protection when using the product, so we did as we were told. We didn’t have any protective goggles handy, so we wore a pair of sunglasses and some rubber gloves. It was a little hard to see that the cleaner was working through the tint of the sunglasses, but they got the job done.

We did get some of the product on our hands, but we didn’t experience any irritation. We certainly advise taking the recommended precautions when using the cleaner, but you needn’t worry that it’s going to scald you should one errant drop make contact with your skin.

We give this formula major bonus points for its mild smell, as well. We wouldn’t say that it was pleasant, exactly, but considering its competitors, the fumes were a lot more tolerable. The scent is a mix of typical cleaning chemicals and florals, but it didn’t give us a headache after scrubbing for a few minutes.

Price: Nice and cheap

When it comes to grout cleaners, nothing is going to break the bank; products range from $10 to around $50 max. At roughly $11 MSRP, this formula falls on the low end of the spectrum and it definitely got the job done, so we’d say it’s a smart buy.

Competition: Mostly more of the same

We tested Black Diamond Ultimate Grout Cleaner against The Floor Guys’ Grout-EEZ Super Heavy-Duty Grout Cleaner and found that both of them performed in a similar manner. Within minutes—and with minimal effort—each product removed nearly all of our shower’s dirt and grime. We would highly recommend both cleaners, but take a look at your needs before you purchase one. If you plan to clean marble surfaces, Black Diamond’s gentle, acid-free formula is the superior option. 

We purchased the Black Diamond Ultimate Grout Cleaner so our reviewer could put it to the test in her bathroom.