I've been using a baster to get the majority of the nap. I also find if I do suck up some gunk, I can wait until it falls to the bottom in the baster, then push it out the bottom back into the vessel. I use the baster until there's just a thin layer of nap left.
Then I pour the remaining thin layer of nap into another narrow glass vessel-I have a double tall shot type glass which is the perfect thing-along with a good amount of the gunk (you have to in order to get all the remaining nap into the new vessel) and then I let that sit for a while to make sure all the nap separates again.
Then I managed to find the perfect thing for getting the rest. I can't even remember where I got it but it is a very small (10 mL) liquid dropper/eye dropper. The glass tube juts out to the side at a 45 degree angle right at the bottom, and the hole on the end is only a couple millimetres wide, so it's super accurate and it sucks stuff up from the side. I can put the dropper straight down into the glass, and I don't get any gunk! Again, putting the dropper against the side of the glass so I can see precisely what I'm doing. When it gets right down to the last, I find tipping the glass to the side helps pool what's left to suck it up. I can get right down to the last drop this way!