You have other options.
It sure would be nice to formally disassociate both because we would no longer have to wonder if someone might try to visit us or contact us in some other way in an attempt to bring us “back to Jehovah.”
No trespassing letter, using the verbiage from your state law, including the fact that you will place them under citizen's arrest if they violate it. Send by registered/certified mail/delivery confirmation. Hang No Trespassing signs up.
Also we would both like to disassociate as a matter of principle, but just without the family fallout.
A matter of principle would be to stop respecting their authority, following their rules, and helping them have the satisfaction of knowing they control you and your relationship with the in-crowd.
http://www.youtube.com/watch?v=eEIJ3YqPbqg
If you need closure, you can do a termination ceremony of your own.
JMHO