Originally Posted by breyman
Yes, a good washing should restore it back to its full loft. If you ever want to wash one yourself, there's lots of good instructions on the web. Pretty easy as long as you have a front-loading washer (or top-loading without an agitator), some down soap and the time to run it for a while in the dryer on low/no heat.
Yes, I checked Western Mountaineering's instructions. They don't see a problem to washing it at home. However, I don't want to do it in the bath tub, and the washing machine is only normal household size. I had problems washing a synthetic comforter due to its size, which makes me hesitant to use it for the down bag. Also, it seems the best thing you can do is, wash down and bag separately. Down is best washed at high temperatures; the synthetic shell doesn't allow this. So the sleeping bag cleaning services offer to wash down and shell separately. They also refill lost down. The price is not that bad, considering what I paid for the bag, and how many times it kept me warm and cozy
I'd probably wash a down under quilt in the washing machine, though. It's only a faction of the size of the sleeping bag.