It's pretty gross and unusable. But I wash them in some gentle soap until the water is clear and hang them out to drip. When no more water is dropping off and before they are dry I blow dry them bit by bit until all the feathers are fluffy and dry. This can take 20mins or so. A long and slow process but at least they don't get all tangled up like if you put them in the dryer. They finish up like this.
Now for the bundling. Some of the feathers are really thin, some are beautiful and thick, some are fluffy, some are skinny. I put them together sometimes in bundles of three or sometimes 4 or 5 depending on their thickness and that of their stalks. I am trying for lush bundles with thin stalks. This I usually can achieve by pulling off the fluff on one side of the feathers. There is waste of course, in this case an ice cream tub full of broken feathers, too skinny feathers, just unusable feathers and fluff from the sides.
From one string 120cm long I managed 280 bundles. Now I am averaging 55 bundles per feather row on my cloak (which in this case is every row) which means I should get 5 rows from one string of feathers. Mostly the feather and stalk are followed by two whenu instead of three, as is usual, but the thickness of the string requires it. My cloak has 230 whenu from the new thick string from ICB and is 95 cm wide. The new string is nice to work with and the work is going quite quickly. It is slowed down by the working of every row feathers, and their bundling takes time but I am happy I will have something to show Saturday week when we have our next all day weaving group.