I never heard that, So you would leave your betta in a sealed bag for weeks?
Anyway even if the betta made it, The bad part is. And this is where bettas that bite there tail during shipping. They are sitting in the dark, In a little bag with there tail hitting them in the face some times. They don't no which way is up. Could you imagin if you were locked in a black room that you couldn't see your hand in front of your face, And then the room is tossed around getting shipped to another country or state.. Very stressful and crazy..