It's funny that folks say you have to floss sockeye to get the fly in the mouth; the first time I fished for sockeye, I had them move to take the fly. The first one grab I ever had (on the Kenai), I was lifting the fly from the bottom (nymphing), and a fish came out of nowhere off the bottom to grab it. THey were super bright, spunky fish.
Tell yourself what you like, I use red "nymphs" for my clients who like to think they're nymphing, I also use bare black hooks. I find no difference in the amount of fish hooked in the mouth. It may look like sockeye are trying to move towards your fly, but they are probably traveling down the leader that is already caught in their mouth. Its a meat hunt, they're delicious, but I wouldn't kid yourself. I'm sure 1 in a million will eat a nymph....and if you're in the right drainage, that might be good enough odds. I've accidently flossed them on dry flies when they've rolled with their mouth open as well. -Love Dan