I happen to think it is not helpful when talking to J.W's to call it a Cult, you simply go down a blind alley and talk about semantics.
To show them how cults and mind-control, high-control groups work, and let them draw their own conclusions is probably better.
But I have done that, and still received the "So what?" attitude, "we have the Truth, and whatever the faithful Slave sees fit to do is O.K by me".
They cannot see how controlled their minds are.