I know it's not rated for damp locations, and it sounds like it definitely got damp. I'd replace it on principle, especially if it was submerged in salt water. It may act fine now, but I imagine you'll have corrosion issues to deal with in the future.
YODA:
corrosion leads to high resistance
high resistance leads to heat
heat leads to fire
fire leads to sadness
And that's to say nothing about all the j-boxes and devices that should be replaced too. I'm guessing the drywall needs replacement because of submergence, and since you have the walls open, do it correctly now. You'll just have to tear open the walls and replace everything later if you don't.
