I have rosacea and this doesn't cause a flare-up at all, which was a concern. And a little goes a long way, so these last a while. I know some other reviews have mentioned the scent...I have a very sensitive nose and this hasn't bothered me at all. It's rather benign.
I wish it would come in a two-pack since I keep one at home and one in my gym bag. Keep in mind that if you order one in the summer and it's a hot day, this will soften. Another reason I would like to order two in the spring and get me through the summer. The packaging does tell you to not leave it out when it's being delivered, but if you can't be home it could get mushy. Nothing too major, but you will notice some patterning from the muslin and it may be a little misshapen, but it doesn't affect the quality of the stone (see photo).