Hm, I'm not sure how your fungia would handle it, and I would definitely wait for someone with more experience or feedback chime in -but, perhaps an iodine dip (Lugol's, TMPCC, Revive, KM TechD) might help prevent infection of the existing wound?
Dipping is fine, although I'd rely on light puffs from a turkey baster to keep the area clean of detritus in order to prevent Vibrio or another infectious critter from starting in on the healthy tissue. If it isn't receding any more, I'd reckon it's going to heal up.
