PUMIE JUMBO U.S Pumice Scouring Brick, Large Scale Heavy Duty Pumice Cleaning Brick for Flat Top Grills, Griddle Stains & Grease, Jumbo Pumice Cleaning Bar for Rust, Tiles & Pools - JPS-12 (Pack of 1)

The prior owners of my home had a long, narrow bath mat with a rectangular grid on the underside. How do I know that? Because when I moved in I found that the bottom of the tub was covered with dark gray hard water stains in the form of a long, narrow rectangular grid.Comet plus elbow grease didn't put a dent in it. Neither did vinegar and baking soda, Scrubbing Bubbles plus bleach, or Kaboom. Those all left the surface feeling nice and smooth, though, so I figured this stain just went too deep to be touched.Then I bought a steam cleaner, because I hate breathing fumes from cleaning agents and had thought of several potential uses around the place. When I tried it on the tub I noticed that the steam was actually fading the stain slightly, so I really went to town on it. After a lot of effort I realized it was going to take many, many steamings to really get rid of the stain, if it was actually possible.But knowing the stain could be faded sent me looking for other ways to clean porcelain, and when I saw this brick of artificial pumice I gave it a shot. The chance of a cheap, low-tech, fume-free method of getting this stain off was too much to ignore....And it worked. My tub is gleaming after maybe 30 minutes of work. And now I won't have to buy a new tub (or conceal the stain like the real estate stagers did) when it's time to sell.Get the brick wet and press down a bit while you scrub --- I had to keep reminding myself to press down --- and this thing will grind away tub stains. Switch it around in your hand from time to time to keep it wearing evenly, because it wears pretty fast. Rinse off the porcelain a few times during the process so you can see what spots you're missing. Stand the brick on end for touch-up work around the drain and where the tub floor meets the walls.

Used this pumice stone to clean a headstone at the cemetery. I almost used the whole block, but it cleaned up nicely to original shine

Scrape the ring in toilet and buildup around faucet. It worked very well. Was broken off a little at the end but was able to use small pieces for small areas.

Used to remove calcium from pool walls and worked perfectly

It works OK but didn't make it around my entire pool. Too soft.

We have had the most difficult white ring on our pool tile and have tried everything including professional cleaning. Nothing really knocked through it or took it all off. With the other items we have tried, you scrub and scrub and scrub, then scrub some more, and there's barely a dent in it. Other things started to scratch the tile. This big brick thing is amazing! It cuts right through the white scale build up on the water line of our tiles. Now, to do a whole pool is going to take some time and more than two of these. While it does not eliminate scrubbing, it take a LOT, LOT less scrubbing than anything else we've tried AND it cleans the tiles SO much more thoroughly. It is nice to find something that actually works!

I have to purchase these once a year to do pool tile maintenance and usually by another brand that offers a 3 pack of smaller bricks. Figured 2 larger bricks is better. Incorrect. These are very soft, much softer than the other ones i purchased. It took both of these to do the same job that one of the smaller ones would do. So the smaller ones must have been harder. Yes they were. So the softer ones must be better for the ceramic? Yes they are. It's just how hard is too hard and how soft is too soft is the question. For my appication on pool tiles these were way, way too soft! and they cost the price of 6 of the other ones. Monetarily these are 6 times more expensive to use than the ones I was using before. Finally they didnt even get all the calcium off either. So that;s a fail.

I bought this to clean the calcium from the tiles in my pool. The product works well, but it wears out pretty quick. I'll need to order another one to finish my pool, but it's good for the time being. Overall, good product.