Hi aandorn, Welcome to All Things Plants
I've always heard that the white felt-like substance on the fronds of
Common Staghorn Fern (Platycerium bifurcatum) helps to retain moisture so it should probably not be wiped off. Hopefully your staghorn will not brown and die but I think if the plant is healthy, it should recover just fine and be okay ... even if those current fronds die, the plant should produce anew from the basal frond. You can read more about the common staghorn fern here:
http://www.sandiegozoo.org/CF/...
http://www.missouribotanicalga...