I could swear that I read of someone that uses the paper egg cartons to make their wads. Unfortunately, all my searching has failed to find where I saw the remarks.
I suppose you could break off a chunk of the carton and test it with the flame from a match or lighter. If it burns without showing signs of melting, then it would probably be worth trying a few in the gun.
Disclaimer: If it works, I will gladly accept due credit. If it screws something up, it was all your idea in the first place.
