You can try dripping water on the side of their beak and letting them take it in, or even dipping the tip of the beak to get them started. Is it possible there are also lice/mites present, or some other problem going on as well? Any chance the feed isn't up to par, that it got wet, or wasn't fresh when you bought it? This does sound like a really bad reaction to molting, if nothing else. I know it does make them uncomfortable.
One way or another, I'd work at getting them to eat and drink, and probably add a supplement to the water, maybe a little Poly Vi Sol or other vitamins / electrolytes (also sold at most feed stores.) Attractive, nutritious snacks like scrambled eggs are a good idea, too. I wish you luck.