I suppose you can "cook" some feathers with steam; but it would take a lot of steam to do that.
What you're doing with steaming is two things:
1. you're removing any dirt and grime that washing has left behind; particularly dirt that keeps the barbules from sticking together (barbules are the tiny "velcro-like" projections that are on each feather barb; the barbs are the feather fibers that you can see coming off the stem (rachis), the barbules are so small that, in general, you need a microscope to see them clearly). It's the sticking together of the barbules that makes the feather barbs lie together and forms the basic shape of the feather.
2. You're softening all of the components of the feather, the stem, the barbs and the barbules. This softening is what Ard is referring to when he says that you can bring the feathers back to life with steaming.
Once you've steamed a feather, take it in your fingers and smooth out the stem and the barbs, so that they look as good as the best feathers on your pheasant skin. When it dries; which doesn't take long with a steamed feather, it will look as it should and then it's ready to be used for fly tying.
Here are a couple of useful links for you:
feather barbs barbules - Bing Images
In my experience, there are feathers that are beyond saving. I think it's best to simply throw those feathers away, since there are plenty of feathers on a good skin.
Good luck; let us know how it works out for you.