It has been my experience when riding that it rarely does any good to show a horse something he's afraid of. A horse's natural instinct is to move away from Scary Objects really fast. Making the horse stand still (or worse, approach) and look at something he'd rather run away from is akin to saying, "I swear to God, it'll only hurt a little when the lion takes a bite."
I wouldn't believe me either. I'd leave.
And trust me, if they want to go there's nothing you can do to stop them.
So what's the best thing to do since trying to make the horse walk up to the Scary Object puts you on the Scary Object's staff as the waiter who serves the main course?
Stay on the horse's team. Utilizing the horse's comfort zone is a quicker path to restoring calm. Therefore, since two things horses do very well are moving and sticking to a routine, it's a good bet that riding a simple routine he's familiar with and good at will help. Because the routine is familiar he knows what to do, and what is expected. Therefore it's safe. Because he's moving he's cooperating with his ancient fright/flight response.
Pretty soon, as he's doing the safe, familiar job, the Scary Object becomes Just Another Object. This tactic works quickly if the rider starts the familiar job at a distance from the Scary Object where the horse shows only a low degree of tension. Then, as the horse relaxes he can be guided closer if necessary. The more stressed the horse becomes, the harder it is to get his attention and restore calm. Also, the more thoroughly trained the horse, the more comfort there will be in his job—and the quicker the Scary Object loses its power.
Aren't we like that, too? If the unexpected occurs and we can get right into a well practiced routine we stand a better chance of getting our heads back on straight. People in high risk jobs know this. That's why they train so much. Since stress is part and parcel of our everyday lives, we can adapt this tactic to help us manage what life throws our way.
Have you developed any routines that keep your stress level down?