Alright so my new lease horse is and arabian gelding named outlaw. He is a very sweet boy but has one major issue that I would like to try and break him from.. When ever you go to tighten the cinch and he is tied up he will rear and jerk back(i have gotten him not to do this once but only out of luck). I have been told to carry a crop when im saddling and when he goes to go back give him a nice crack on the butt .. but I wanted to see if there was another way to break him of it. No its not the saddle hurting him as he does it with everyone and everyone has a different saddle,he has just learned that if he does it enough people usually backed off (the lady who bought him from the barn then basically abandoned him for a year and a half , we worked him eveyr now and then so he didnt get to sour) . We have gotten him retrained to be a very nice horse besides this one problem. So what would you guys suggest.
P.s. The barn owner and one of my trainers both suggested the smack on the butt so don't attack me about permission. They would rather me work with him on it then let him get away with it .