Contributors to this thread:
How to wash down sleeping bag?
Most have instructions, but washer on gentle/cool with sport detergent or similar, dryer on low heat or no heat. I've only washed a couple times but worked extremely well.
BTW I try to limit the need for washing the sleeping bag by always using a silk liner or a warmer liner in colder weather, which I can wash every time after use.
They generally have instructions. There are products specifically for washing down. I hand-wash down bag in the bathtub after cleaning the tub.
I think I have washed it, at most, once in its life - getting a "life of its own"!!!! Definitely time!
I've always just stored mine inside out and hung from the ceiling of my storage room. But, I also always wear a light weight pair of merino wool long underwear when I use my bag. That seems to keep the "funk smell" down to a minimum.
I was going to suggest putting it in a Hilleberg Atko tent for a gentle rinse cycle. LOL
But seriously, REI has a section on sleeping bag care and cleaning that looks pretty good: https://www.rei.com/learn/expert-advice/caring-sleeping-bag.html
What Ike said. I use a silk liner with my bags and quilts to help keep skin oils and crud off of them too. I try to do “surface” cleans with anything that has water resistant down as opposed to submersion to try to avoid having soaps impact the “water resistance”
Check out Nikwax Down Wash Direct. Great product, I use it on all my down filled gear. It's safe for use on hydrophobic or regular down gear. Just follow the directions.
I also recommend the use of a bag liner and only wash my down gear when absolutely necessary.