Wow that's one crazy climber!
Hmmm... I don't like the hose idea for only one reason. You said you were going to call her first! That may translate to her that if she comes when you call she gets the hose, not that climbing over the fence is unpleasant. The best way would be to wait until she decides to escape, and get her wet with the hose without her seeing that it's you! Especially if she usually escapes when you aren't paying attention. It can be so hard to catch them in the act like that, though. My dogs always do their mischief when I'm not looking. IE they would never dig a hole when I was nearby, but I know those holes are getting in the yard somehow!
I am totally pro shock collar for things like preventing them from getting out of the yard. Getting a warning beep and then a zing if they continue to try to get out of the yard is nothing compared to getting hit by a car. I don't think shock collars work as well for training commands like sit, etc., - those are best trained with positive reinforcement. But for a negative behavior that's only occurring out of your sight and could be dangerous, you shouldn't feel guilty.