Yep, Thats the bad part with these saws. Nobody makes new air filters for them that I know of. Occasionally you will find a new old stock filter on ebay, but they usually demand and arm or leg.
Just wash the best you can, and air etc. I had one one time that the flocking was gone. I tried using a foam material to put in the filter. Wasn't great, but it got me by, till I found one. I guess there is other air filter material you could cut and make one also. Just have to get creative till ya can get a new or better one.
Gregg,