Wadoy Pool Stain Eraser for Plaster Concrete Pool Spa Pumice Stone Rust Spot Removal?2pc?

1.Q:Can this be used on the tiles around the top of pool? A:we can use it to remove calcium buildup with this tool, and it didn’t scratch the tiles; it takes time to use this, but the results were worth it; 2.Q:Is this really pumice stone? A: It is much more dense than the typical pumice we've used. However, it could do a good job removing scale from our pool tiles without scratching them. ***Use this rust spot / stain remover to eliminates most types of stain and deposits including rust, scale, calcium deposits, and many other stains on the plaster concrete pool. ***Easily attache to standard pool telescopic pole. ***Attention: Do not use this pumice stone on your vinyl liner pool surfaces