I have a large male German Shel. He is not afraid of a gun shot, thunder, or most any sound but he hates a clicker. What do you think?

I have a large male German Shel. He is not afraid of a gun shot, thunder, or most any sound but he hates a clicker. I can't get him use to it because if I use it he avoids me and I am afraid it will damage our trust bond, so I don't use it. He needs to get use to it though. What do you think?

Roz