I have had 5 or so gorgs in my time. Two of my current gorgs I have had for 8 years now. I dipped one once in a weak solution of iodine, it started emitting something turning the dip solution greenish, i put it in my tank right after seeing that and a few days later it was dead. My other gorgs have been fine, i did loose my yellow finger gorge after a while but it was not in the best shape when I got it.
Personally i will not dip any more gorgs. just look them over very closely for pests.