For zoanthids, I use a RO water bath with a little Lugol's or SeaChem ReefDip. I'll let them soak for a few minutes and then inspect every polyp I can for nudi eggs or other hanger-onners. 2x readers, good lights, tweezers, and a magnifying glass.
For others (LPS and SPS) I first use tank water w/Revive and then into tank water w/ReefDip. I see more critters (snails, starfish, pods, etc.) die quicker with the iodine-based dips than with the Revive. My hard coral treatment is likely not sufficient for killing redbugs or nudi eggs.