Isn't there some kind of felt like spray available at craft stores?
You mean flocking?
I don't think it would put up well under actual use underneath a dust washer. It's typically used for looks. eg, scale models, dioramas, crafts. It's not used for "functional" items like felt is.(see edit) It's typically two parts. There is a glue that you apply and there is bottle of fibers that you apply once the glue "tacks up". Don't bother with the glue as it's just glorified rubber cement really. You can usually buy the flocking components separately, so I just bought the necessary fibers and used my own glue mixes which is generally thinned Elmers or whatever spray on glue I have on hand that day. Even wet paint will work but doesn't tack up as well.

If they do have some sort of all-in-one spray can of flocking, I've never seen it on my trips to the store.
And no, I'm not talking about Christmas tree flocking. Totally separate beast altogether.
Edit:
I just remembered the automotive industry also uses flocking. The glue composition is water based acrylic. I've never used them because I always had the hobby stuff readily available. Prices are pretty reasonable, you can get the stuff you need in small quantities for under $20.
http://www.flockit.com