I also woke up during exams, actually a couple of different colonoscopies. I was in so much pain that I really thought the scope was going to come right through my stomach. My GI said "ok, we're going around a bend" then I think they gave me more drugs and I was out again. This hasn't happened for probably the last 3 or 4 times I had a colonoscopy. They use a better cocktail of drugs now, they are much stronger, THANK GOD!!
If I liked apple juice, I would try your method, but apple juice is one thing that I hate. Glad it worked well for you. I still find the best way to drink that crap is to use a large straw (like the ones that come in a sports bottle) and just keep sucking it down non stop. Don't let it swish around in your mouth. I still dread it every time. I'd rather not eat anything for 3 days.