Agree. Probably best to handwash first, or at least soak in a bucket before putting in the washing machine. I know that stuff seems really fine, but with some manual agitation, you should be able to get a good amount of the stuff out of the fibers.
Costume Con - Kili in a dress
Atomic Lollipop - Come visit me at the Make-Your-Own-Button free craft booth!
Polar Chill - check out my costume DIY panel and workshop
FanExpo - Iron Man Mark VII version 2, Pacific Rim Jaeger pilot?
FanExpo - fem!Iron Man Mark VII - The Iron Man Armor Project
Atomic Lollipop - Vanellope von Schweetz; raver!Sailor Mars