The trouble with a brown paper bag is you wont be able to see where you are going, and hiding from the problem doesnt generally help! lol.
No really, i have not tried it but a friend of mine swears by putting his bud in a brown bag to dry. Even in between sheets of newspaper! I guess the most important thing is airflow because of the risk of mould so if you watch them carefully i imagine they would be fine.
See what anyone else says though cos its only information from a mate, not from experience.