The stones are indeed a real product often touted in whisky collectors mags, etc. . They do not dissolve or in any way alter the taste of the whisky except by making it cooler by a few degrees. They are washable and reusable. They are not a gag.

Soneone once told me that only two things should ever touch fine whisky---a glass and my lips. Works for me. Straight, neat, no ice no water, no chaser---let it linger in my mouth for half an hour after the last sup. I am salivating now just thinking about it.