Is it the noise he is afraid of or the actual spray mist?
Few things to try...find a safe empty spray container(old fly spray container should work) and put water in it (so you don't waste the spray). Every time you mess with him, try spraying. First try spraying beside him (not on him), just towards the ground. Then start on the lower front legs. Talk to him, ease him through it. When he is comfortable with the lower legs, move up a bit, then try the back legs, slowly move up the body as he gets used to it. Seems like they sometimes don't like there back sprayed. Just take your time.
Another thought is to try one of those hand sprayers that are used for applying stuff to your garden. They make small inexpensive ones that you can pump up ahead of time, and then just press or squeeze a lever to spray. Then all the animal has to deal with is the mist, and not the noise.
Good luck!