Just adding my experience to the mix here...
My friends and I started this quest last weekend then went and spent just over 4 hours on the barge in Carpenter's Landing. We got 2 drops during that time. One was off an Ooze, the other was off a fished up Fishtrap. This is with TH (but no TH2).
Oozes only spawn at night. The one or two other mobs that spawned on each barge trip never dropped - pugils, crabs, normal flytraps.
Edited, Mon May 23 12:07:30 2005