On a good day I use 'church' when talking to Dubs, usually describing their religion, or KH as 'your church', their doctrines as 'what your religious leaders teach'.
The grammar I use doesn't give them wiggle room to pronounce that they are 'not a church' and none have tried to 'correct' me.
To make them feel comfortable, I make it clear that, although I was born to members of their church, I never joined it and don't follow a bunch of men in the Vatican, Utah or Brooklyn.
Never let them get away with anything that makes them look at all special or different. There is always someone doing whatever it is that they are boasting about, and probably doing it better.