You can do the dip with RO/water, FWE ( flat worm exit ), lugols solution in a separate bucket....
FWE to kill nudi's, pluck out the eggs via' pinchers or what ever you have, lugols and pinchers for snails and other hitch hickers.
after that , leave them for a couple of weeks in a QT as they heal and watch for further hitchhickers that may have survived the dip