Welcome to the site! I found the Opiyuk phase very challenging as well. Not my favourite drink! To begin with I had to hold my nose and just chug it down like medicine.
It's great that you've done your research, the more you know the better you will cope after surgery. This is a very supportive site so make sure you ask plenty of questions, usually you'll find someone who is facing the same problem. If not try the search button at the top of the page. But no matter how much you know its still a scary time leading up to surgery.