How to clean down.
You can wash down. Here is some info.
Manufacturers are required by law to put on the label
ONE way that the item can be cleaned. That doesn't mean the
BEST way.
Depending on the color, (will the colors bleed?) I would wash it.
Down's insulating ability comes from loft. Basically, it is the how much it expands to trap air. Soap residue will cause down to lose lofting ability. So will bleach. It will break down the filaments and it won't trap as much air. Liquid fabric softeners will also cause the down not to loft.
When washing, use cold or warm water, never hot, on a delicate setting (It won't get "beat up" which will cause the filaments to break. Also, wash it by itself for the same reason. A mild soap, that rinses thoroughly. (I don't use as much, and will run it through an extra rinse or too, to make sure all of the soap residue is gone.) I also prefer liquid to powder for that reason.
Then dry on low with clean tennis balls to fluff it up. If you don't have tennis balls, you can use dryer balls. I have even used clean, freshly laundered canvas sneakers. It will take a REALLY long time to dry on low. I usually will dry it most of the way (it is fluffed as much as possible, no clumps of down), then hang it up to finish drying.
