John,
Your suggestion is the best way there is to KILL a bunch of eels. Learned this
the hard way many years ago. If you put them in water w/o an aerator they soon
use up the oxygen and drown. The best way I found to keep them alive is to use
a bucket in a bucket arrangement. Drill a lot of holes in the inner bucket to allow
water and eel slime to drain to the outer bucket. Put seaweed in the inner bucket along
with the eels. To keep them for several days add ice periodically. It makes it
easier to handle and hook them. They come alive when they hit the water. I've kept
them alive for over a week this way.