It seems you're asking how to wash down feathers!

Here's how you can do it:

First, gently separate any loose feathers from the down. Then, wash the down feathers in a gentle cycle with a mild detergent, preferably one designed for delicate fabrics. Use cool or lukewarm water, as hot water can damage the feathers. After washing, rinse the feathers thoroughly to remove all traces of detergent. Finally, gently squeeze out excess water and lay the feathers flat to dry. Avoid using a dryer, as the heat can also damage the feathers and make them lose their fluffiness.

Be patient and gentle, and your down feathers will be clean and fluffy again!