I have a hard time being dishonest, so I feel your pain. But honestly does not compel us to say all truths, only to not say things that are untrue. Your thoughts are your own, you are not compelled to admit them. Can you think of some ambiguous statements that you could respond with that would maybe give a hint of your true feelings (but obviously nothing that would be considered apostate or that you would be called on ).
Like if someone says "The governing body is really looking out for us" you could say "Yes, they make sure we always know what we are supposed to think about things". It's true, but is a fraction more honest than they usually admit to.
Or answer a question with a question "Hmm...., Do you really think so?" .
Or just a non committal "hmmm, I suppose so".
Sometimes lack of confirmation could do more good to help people along in waking up than open confrontation. These people have been conditioned to think a certain way, contradicting them would not only out you, it would cause their fears of apostasy to kick in and become fearful, so not help them out at all. You would be doing something much more insidious.
You could think of yourself as a double agent, working to subtly undermine the organization, but without getting caught. It's not easy to do, it's a very fine line you would be crossing here, but it might make you feel better about yourself, that instead of letting people continue on with their delusions you are helping them wake up, even if ever so slowly.