If I told you to go into a burning building... would you? If I shoved you in, how would you feel about me? If I hit you and kicked you, would you think "Why sure I'll go in for you!" Even if I was nice and you liked me, would you just step right in? Even if you trusted me would you go in without any hesitation?
Making/forcing your horse to 'accept' scary things is a much less reliable method than giving horse a little time to learn how to differentiate between what is really scary and what really isn't. If you give them exposure and opportunity to explore without pressure, they then learn to trust you. They learn how to handle spooky situations and they learn how to handle pressure when the two of you are in a spooky situation. As they learn that you'll let them investigate, they'll need less time to investigate and just trust you.
Instead of having a horse spook for the rest of its life and taking the time to attempt to get thru it, why not give them a little time in the first place to avoid it? Just a little patience folks. This is the long-short way.