I used isomalt coral on this cake:
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1604189
I acutally poured mine into styrofoam cups full of ice, but I think a pot would have worked much better. You can see mine are all really small. Be very careful of cooking too long, I burnt a lot of mine (the really dark pieces). I like the idea of putting it into a pot of cold water, it may have helped me!
Hope this helps!