
https://www.youtube.com/watch?v=k6L_ArXCbYs
One caveat...
The YouTube setup refers to not cutting off the bottom of the pop bottle in order to refill with walnut shells because of blowup of the shells when air is applied. You could, with a little modification, use the shell of an old thermos bottle as your container. The "lid" of the thermos bottle is plenty thick for the insertion of the blow tube and you can unscrew the bottom to refill.
Bill