cleaning mallard mount

[Sikk]

I am a beginner, so bear with me. I have a customer who had a leak in his basement. His mallards got soaked and dirty. I am not sure if this was a plumbing leak or a foundation leak.The feathers are matted down. Is there any way to clean these and fluff the feathers and make the mount look fresh again? the birds are mounted on a panel with a support wire holding the birds. He said they are so bad he is considering throwing them out. I would like to try and help him out if possible. thanks paul