My ducks sported the wet look when we had that big freeze a while back and all they could do was drink water, not bathe in it. Their pond water was frozen for a week.
My chickens dust themselves in a thouroughly DE dusted area. My ducks don't dust bathe so I just did it for them when I...
I had this same issue. Look under "wet feather" I believe.
I feed all the right things, it was mites that caused it. Now they are dusted with food grade DE once a week top to bottom and their night time pen is dusted. They are much better.
Good Luck!
-Sally