Monti Eating Nudis..help

[Hairytank]

Arggg, one of my Montis suddenly had a bleached whitespot...so upon inspection, I found what I believe to be monti eating nudibrancs..here is the best photo I could get of one of the slightly mangled (removal was not a gentle) beasts..



All of the monti caps appear to have nudis on them at this point... but not exhibiting signs of colour loss/death. The adults were pulled/scaped off. There were none on the digitata or encrusting superman.

Have read about possible remidies such as: RO FW dips, iodine dips, tropic marin pro coral dip, Praziquantel (Prazipro by Hikari), poly ox, peroxide...
Anyone have experience with any/all of the above? Is there a natural preditor?