The trick with the tap, tap, tap, method is you never hit harder than a tap, I have always been able to get a horse in with this method. The constant tapping gets to them eventually. I know how hard it is not to start wacking, but that would be too much pressure, and she might, as you say explode.
A ramp trailer might help too.
The worst horse I ever loaded was a friends, we were about 18 years old, We were at a show and everyone was gone, and we still couldn't get that SOB in the trailer, there was a cattle chute to load cattle into semi trucks, so basically it was a ramp about 12 feet long, one horse wide, going to about 7 feet high with 5 foot tall sides. We backed the horse on to the ramp, and I backed my trailer to the bottom of the ramp, the owner got behind the horse on the ramp and gave him a good swift kick in the butt. He walked down the ramp and right into the trailer.
One of the dumb things I have done with a horse, but it worked.
I feel your pain!