getting call ducks white

[dutchhollow]

Any suggestions for getting call ducks white for a show? I think they hay in their box has stained them, and I read not to wash them?
Thanks

 

[Kevin565]

Most of the breeders around here take them off the ground awhile before the shows. You should also limit their corn intake. I know they make whitening shampoo for dogs but I'm not sure if it works on feathers.

 

[dutchhollow]

They havne't had corn, they were up on wire, but I had hay in the box for them to get off of the wire.
I have whitening shampoo, but have read you aren't supposed to wash duck with soap?
Thanks.