I've read that if you dry barehand a trout you will remove the protective slime promoting fungus to engulf the fish,leading to it's demise.It's best that you always wet your hands before you handle any fish that you want to release.
Agreed. Wet your hands and that reduces the amount of slime you'll rub off. If you handle a trout with dry hands the slime just glues itself to your hands, and thus not the fish.