Feather duvets are commonly sold as the inserts of the duvet. The duvet itself is usually a separate cover that can be unbuttoned and cleaned. Sometimes people use the duvet insert as the top cover and the insert becomes dirty or stained. This poses some problems because a duvet insert is quite heavy when wet. Laundering the insert in standard laundry equipment may cause damage to your home machinery. In addition, the wet feathers will mat together and the duvet insert will come out lumpy. If your duvet insert claims it can be laundered then take it to a laundromat with a commercial washing machine.
Apply a stain remover to any serious stains on the duvet. Sometimes it helps to run just the stained area under a faucet to scrub out the stains by hand.
Take your duvet to a laundromat with a commercial capacity washer that is designed for at least a 22.7kg. load as wet feathers are very heavy.
Add a gentle easy-rinse washing powder to the wash and run the duvet through the wash cycle. When possible, rinse and spin it twice to remove any soap residue. You might even want to rearrange the duvet between your two rinse and spins as it may have wadded up into a ball.
Place the duvet in a large, commercial dryer with three to five clean tennis balls. These will help re-fluff the duvet as it dries.
Feather duvets should be washed only infrequently. Clean them regularly with dry cleaning and use a duvet cover to protect the surfaces of the insert. The cover can easily be laundered using your regular washing machine.