I just washed mine a few months ago and would recommend this: 1) wash the bag in a bathtub by hand, gently with down detergent, 2) put it on the side of the tub, or prop it on something (eg a chair) in the tub and let some water drip out for a few hours, 3) put it in your drier (but make sure it is clean and doesn’t have sharp rusty faults inside) and dry on Low for hours and hours; add 2-3 tennis balls inside the drier to help it stay puffy; also, open the direr once every 15-20 mins or so and fluff up the little balls of dawn by hand. In a day, or so, you will have your bag sparkling clean and as fluffy as new.
If you have any bad stains, you can pretreat those with a toothbrush, warm water and mild stain remover or just using the liquid down detergent and let sit for about 30 minutes before washing. I also detach the hood and place it in a to keep the metal parts from making noise.
The requires only a half cap for a Euro-sized HE load. Please do NOT use your regular detergent – the enzymes in it are harmful to the down and feathers, and it lacks the ingredients in specialized down detergents that condition down.
Thanks for this very informative article. I have both the W3038 and the Miele Down detergent and was wondering what would you do differently when washing a down comforter in the Miele? Our’s is fairly soiled as our pets take over any available “fluffy” spot in the house.