Bruce,
There was a show on the National Geographic channel last night on the snakehead carp problem they are having in Maryland. The reason I mention this is that you said you need a way to tranq them, they used some type of oil, I can't remember the name. They said it was a topical numbing agent for humans, but acted as a sleeping pill to fish. If I see the show on again I will write down the name of the oil. But you could probably drain down the hot tub, add some of this oil, and wait for nap time for pacu.
Sounds like fun, send pics if you have any, I would love to see your fish.
