Haven't tried it, but suspect any sort of sifting device (even a piece of paper bent into a "V") would work, when paired with an inflatable balloon.
Inflate the latter, rub on clothing, carpeting, or fabric covered furniture to charge the balloon's surface, and then slowly and carefully lower above the static grass sprinkled onto small blobs of white glue, in order to get them to stand up.
The trick is getting the appropriate height so as to attract the grass to get it to stand up, without getting it too close to cause the little fibers to leap through the air onto the balloon's surface.
I suspect if that occurs, you can just wash them off, let dry, and then try again.
I had the exact same idea a couple of weeks back already. The problem I encountered was that the grass is indeed attracted to the balloon, and even stands on end quite well, but it avoids, in clear-cut circles even, the places where you put glue on the surface of the balloon. By all means try it for yourself, who knows there might be some variable that fixes this!