Zoa eating nudibranch.... :(

[Jeff000]

How can I rid myself of these?

Taking zoas out and dipping isn't really an option at this point.

I've read flat worm exit at 4x the recommended dose will rid them, if I dose twice 2 weeks apart. But I am not sure if this will kill the rest of my tank. I have lots of inverts that would be impossible to remove.

Is there a fish or shrimp that will eat them?
I have a 6 line, but not sure if he eats anything.

I do know where they came from based on my purchase dates and the first and largest effected colony, but just be careful in your dipping and visual inspection for eggs.

Picture.