My friend and fellow pastelist, Jude Galbraith brought a blue feather duster to the wine country retreat workshop in Dundee, Oregon a couple weeks ago. No, she didn't want to keep the retreat clean for us. It wa s for her pastels! I was surprised and charmed.
It works like a charm to clean off your lightly used pastels. Use it outside with a mask or be real careful of wind direction. It won't clean all the sides, obviously, but if you just got things a little messy, it's perfect. If you really need to thoroughly clean them, I recommend corn meal.