Review on 🧽 20-Pack Pumice Stones for Cleaning - Pumice Scouring Pad, Toilet Bowl Ring Remover, Bath, Household, Kitchen, Pool Cleaner - 5.9 x 1.4 x 0.9 Inch (Gray) by Heather Phillips

I have very hard water. I bought these to remove heavy limescale/limescale build up from pool tiles. Plus, they wash out completely in about a minute, which is why I now use them for toilet/sink limescale. They are better for light buildup on these surfaces, but if you are looking for a high hardness pumice stone for heavier tasks, choose another (I have used a pumice insert on a pool accessory before and it was much harder/stronger) . /more abrasive and effective than these - I think you can find this model at Revain as well.)