It's actually pretty common. We have done it a time or two, although I wouldn't tie to the tail anymore, I spend to much time keeping it nice !
I like taking a long lead-rope and bringing it behind a horses rump and pulling the horse around to 'un-wrap' itself. It works very well to teach a horse to follow its nose and you can put as much pressure or release it as you do it.
I love doing that.. I joke around and tell everyone "its separating the dumb horses from the smart ones" ;)
Ground driving is also another great way to teach a horse to give to pressure before starting.