Wilder,
I haven't used the Clout for likely a month now, so I don't think that is causing the irritation.
From the articles you sent, this is the most like the fish are acting, but I'm not sure if that's it.
Chilodonella
This is a dangerous parasite that effects fish. The symptoms are excessive rubbing of skin, laboured 'breathing', loss of appetite, lethargy, clouded skin and fish spending too much time lying dormant on the aquarium floor. Chilodonella is a dangerous parasite because it has a wide temperature range that it can live in, and also because symptoms don't show up until late in the disease when it may be to late to save the fish.
Parasite medications easily treat Chilodonella - just remember to remove any activated carbon from filter.
The picture of this worm looks closest likely to the ones in the tank. The just seem to float in the water twitching back and forth, I can't see any of the little ickies protruding from the fish, but I may just be missing them.
Camallanus species ( Figure 12 ) infect the gastrointestinal tract of cichlids, live-bearers (including guppies and swordtails), and other species of freshwater fish. Usually, the first evidence of infection is a red, worm-like animal protruding from the anus of a fish.
Is Nospherith's recommendation about Nuking the best bet, sure hate to do that if there are other ways?