Last summer, I bought a Monti from someone who used wrasses for `eradication'. Hadn't seen any in months ... weren't going to be an issue for me. They were long gone ....
Needless to say, a few months later, I had a Monti nudi problem.
If you trade, `natural predators' are a joke IMO - as you can easily have a few eggs left ... and pass along the plague.
Sure, you won't see any ... but does that mean your coral [and any frags/etc] don't have a single egg?
Might be good for you - but if you trade/sell ... might end up infecting the next tank.
I know I'll never buy, trade, or take a freebie from the source of my Monti nudis. Maybe wrasses `work' for him + his tank ... but not for his reputation for selling pests w/ livestock.
IME, while high-intensity Lugols can work, Levamisole as outlined by Mitch Carl IMO is by far the best choice. Natural predators might solve your problem - but might still leave you spreading them to others.