A Scientific Expedition?

Spent the day today with one of my fellow aquatic gardner buddies tooling up
the Hudson from Piermont, NY to Saugerties.  On the way we noticed some 5' -
6' Vallisneria type plants growing in the more northern parts of the river
(past Kingston).  We stopped and collected a couple of dozen of the
Val-lookalikes as well as some duckweed which was abounding.

After bringing the goods home and cutting them down to 2' or so. I washed
them thoroughly and put them in a gallon container of water with about 2
tablespoons of AquariSol (with Copper Sulfate) and plan to soak them for
three days or so to [hopefully] kill off any inverterbrates attached.

My question is: am I making a mistake by putting them in my plant tank?  I'm
sure there is risk involved, but what exactly is the risk?  Are there any
extra precautions I haven't considered?  Is there anything else I should soak
them in before committing them to an otherwise healthy tank?  Does the
duckweed need any special consideration?

Any and all answers would be greatly appreciated.  I am leaving for MacWorld
Tuesday morning and won't be returning until Wed. night so I don't plan on
acting before then.

Adam Aronson
Sr. Systems Engineer
TransNet Corp.

aaronson at aol_com
aaronson at soho_ios.com