I have used CDC for years. I had a natural supply duck hunting, just pluck all the feathers away from the oil glands. Ziploc bags stuffed away of it. The fibers trap air, but the pure thing has the oils on them. But, usually only good for one fish then put them up to dry. The slime wets it down.
I have a killer caddis fly that is simply a hackle tail, hare ear body, and cdc wing. Several others, RS2 spinners for the spent mayflies. Some midges.
I always used natural cdc. I always assumed that you would have to rinse in soap to get rid of the oil for it to take a dye. Then, all you have is the fibers.