Hopsino, are you for real??
You are being incredibly sweet and making me feel very guilty. Thanks very much to you and the rest who answered my post and convinced me that the stones were not fake. Apparently this experiment has been done before - as seen in the above posts. There is even a link to one with pictures on this site.
I am incredibly humbled by everyone's response, and especially yours hopsino. Please feel free not to do the experiment - at least not for my sake. If you would like to do it for yourself then that is a different matter.
When I was asking for a volunteer I didn't want anyone to go out of their way - I was just looking for someone who was flushing anyway. In any case my mind is at rest now thanks to your post and those before it.
BTW where are the Ozarks?
We had snow here in London a week ago today - then today we got the first day of Spring - flowers blooming, warm air, sunshine ... it feels good to be alive.