I think like most things it depends. If you've got family/friends whom you care about that live close by, it make make sense to fade. The tradeoff is you have to live a lie for potentially several years, and it's not a principaled stand based on your convictions. This is a very stressful position to put yourself into. Imagine getting on the stage and giving talks that you don't believe in, many like myself didn't have the stomach for this.
If you don't live close to family, or you can move, then a better option is just to stop going. Quit cold turkey, and don't say anything about it to the family you care about, unless they bring it up or find out about it. When they do, you could just reply that YOU no longer believe it anymore. It's very non-confrontational, and there is nothing they can really do about it except either show unconditional love or reject you because they want to, not because you've been labeled an apostate. When you get visitors just tell them you want to spend time with them and not go to the meeting while they are there. Although this is not completely truthfull it's also not technically lying. You're well within your right to withhold information if you want to.
If you just want instant freedom from worry or future repercusions and you don't care about what friends and family that are in think, then disassociation is defintely the way to go.
I've gone the cold turkey route, and i'll eventually follow it up with a letter of disassociation at some point.