Argh. Nobody told me what a challenge it would be to get the pain-patch off Captain. His fur was growing in under the shaved area, and the patch was stuck to it. Imagine pulling off a 1.5"x2" adhesive patch off an area that's covered with fur or hair. OUCH.
Fortunately, he's a very patient cat. For the most part, he just mewed his complaints instead of trying to do battle.
After a few minutes (ouch! Sorry, Captain) and by applying water (which Captain wasn't all that delighted with, either), I got the patch off. GOOD KITTY, he behaved very well.
Plenty of treats and praise are the order of the day, right about now.