Anytime I've gotten some skinned bird or pieces of hide I've done the following: Make sure I remove as much fat as I can; Place about a 1/4 cup of Dawn detergent and a cap full of Chlorox bleach into a bucket of very warm, but not hot water. If too hot the skin will expand and the hair might fall out. Swish material around and let it soak for a few minutes; Rinse completely; Wring as much of the water out as possible without injuring the skin. Oh, if you just have feathers, after the rinsing, put them in a woman's stocking and whirl it around to let centrifugal force force the water out; Place skin against cardboard and let it air dry. You can dry the feathers faster with a hair dryer. Once completely dry, place materials in individual a zip lock bags with a moth ball or two. Label the bag identifying the contents and date. Keep segregated from other materials for a month. You don't want to risk the possibility of any infestation. I've used this method for many, many years, and it's worked.
Finally, some stuff isn't worth the bother. Enthusiastically thank the provider and then carefully dispose of what you were given.
Allan