Washing a product that contains feathers is much simpler than it appears, so long as you take a little care: down doesn't go well with water and clumps when it is damp.
As far as possible, avoid washing your feather sleeping bag too often and use a sleeping bag liner.
How to clean a sleeping bag
You will have to fluff up the feathers and down at each stage of the washing process:
- Zip up the sleeping bag and put it in the washing machine
- Add some washing balls or 2 or 3 tennis balls (ideally not brand new balls so that no yellow threads come off).
- Run a cycle at 30°C with your usual washing product (less than the usual quantity) or a special down washing product which preserves its insulating properties
- Rinse twice and set a very delicate spin cycle so that the feathers do not clump together