I have, I don't notice any difference when I do. Typically I use a small slow cooker that is actually designed for poppourie. It holds exactly 4 sticks of butter, once it melts I skim off the white scum, and then add trim. I fill it up to the edge with however much that holds, I think a couple cups, I'm gonna measure it all next time I do it to try to figure it up. Any way then I leave it uncovered for several hours, stir and repeat for a total of 5-6 hours cook time. Often times this will end up being late at night, so I just unplug it and leave it till the next day at which point I warm it back up to strain it out. I find this method very simple, no mus and fus with freezing stuff or boiling water, or double boilers and shit. However to each his own, hope it helps.
Oh I also always use dry trim, I'm sure either way would work though.