This is basically the same area as "Growers," though I guess "showers" may experience some shrinkage in cold water etc., it's a phenomenon "growers" live with every day. Check out the thread:
Growers
Here's my minimum,
http://www.lpsg.org/gallery/showphot.../ppuser/263370
and it doesn't take cold water to do it. A cold swim in the sea, and my dick disappears somewhere up inside behind my belly button, as far as I can tell. Have to send the dogs it to hunt it out again, my bollix hide behind my ears....LOL