After every trip I backflush my Point One filter and attempt to air dry it. It seems to take forever (weeks) before I can shake the filter and not hear water sloshing around inside. Is this normal and OK? Should I be trying to blow compressed air through the filter or something? Couldn't find anything on the Sawyer website regarding drying instructions, or if it's even necessary. Just seems like a damp environment would be good for growing bacteria, etc in storage.

It's recommended to run a bleach solution through before storage. Drying one out does take a long time.