Comforters are nice to have on your bed anytime of year. They are warm in the winter, cool in the summer and look great year round. It can be a chore to get them clean again though. This is a guide about cleaning comforters.
I just threw my full down comforter in the washer along with several pair of heavy size 9 flip flops and toddler Keen sandals. I used low suds detergent and 1/2 cup vinegar to freshen things up. I did manually move/refold the clumpy sodden mess a few times to make sure all surfaces really got clean. The flip flops and sandals went in the dryer too.
This works much better than tennis balls because they're heavier and the comforter doesn't tend to wrap them up quite so much. Just set the dryer to fluff for about and hour or so, occasionally taking the comforter out and shaking. It came out nice and fluffy and fresh.
By prematurely gray from South Jersey