I've read a few different ways, I just throw it in dry at flame out and give it a good stir, it works excellent. Defiantly can see a better floc than when I used whirlfloc; and the beers end up very clear in the glass.
From my understanding you do need to store it pretty well. I've got mine in the original bag folded down a couple of times and pegged shut, then put into an air tight container. So far so good.
QldKev