I used the clove oil. It wasn't super fast, but she did pass quietly.
The pond she came from isn't mine, I looked at it and bid to clean it. I don't know about the other fish for right, now, but had she stayed they'd have all gotten sick eventually.
A good cleaning is a good thing now and then, and this one doesn't look it has ever been cleaned. Herons and ducks can bring parasites from lakes. If it's a real bad one it wipes the pond out if not treated, this one is just intestinal.
