Can I use the model to work on phobias?

Hi, a client of mine has a phobia of height, how can I use the model to coach him on that? When I ask him about the thought he has, he says he has no conscious thought but just feeling freeze and afraid of heights. But he can’t explain why. It’s not about the fear of falling, he just can’t tell me why he is afraid, doesn’t recognise any conscious thoughts behind. Thank you