I'm a little late to this thread... I like to pull the drain plug and let the
oil drain overnight to try and get everything out. That is probably a waste of time since there will be plenty of residual in the hoses around the remote filter. I don't leave the filter off for as long since it is in an awkward place. You just don't want to forget you are in the middle of an
oil change and start the sucker up! That is probably the best reason to drain it hot and get
oil back in it ASAP!
On the water thing. There are three kinds of water in oil. Free water (sitting on bottom and very rare), emulsified oil (the foam you see on the cap or dipstick) and dissolved water. The first two are the worst for your engine. The dissolved water is not so much of a big deal and really can't be avoided. Oil at 250 F still has a few ppm of dissolved water. E10 gasoline averages 1,000 ppm water just because the ethanol has as much as 1% water in it. Sorry, but I just had to get my 2 cents in....