Submerse in water until completely soaked. Squeeze the air out of the article to get it wet thoroughly. Wash by hand or in a washing machine on gentle cycle. Use a mild detergent (like Woolite). Rinse well and hang in shaded area to dry. Tumble dry on a low heat if necessary.
Ensure your duvet and pillow are completely dry before using it.

If properly cared for down duvets and down pillows will last you a lifetime.