What do you say to people who think exorcism is hokum?

What do you say to people who think exorcism is hokum?

Michele Kennedy (Exorcist) gives expert video advice on: How do I find a reputable exorcist?; How realistic is the film The Exorcist'?; What's the scariest exorcism you've done? and more...

I can understand how people would be sceptical if they've never come across spiritual activity before. On the other hand, I would say that the exorcism carried out by a therapist does have a real effect on people's lives. Therefore, I think that people should have an open mind about exorcism.