I teach it as something to hold on to so they aren't two-handing the yoke. Once you get comfortable with that, its really not necessary to hold it through the entire flight. I usually just instinctively hold it through the takeoff and up through the initial climb, then once that's done, let the hand go. Only a couple of times have I had throttle creep even on takeoff and its usually slow enough that there's easily time to process what's going on, and its only been when my had was still there on the throttle knob but not up against it, so a simple push forward and climb performance regained. When you're pitching for Vy, throttle creep is usually so slow- ****In my experience****- that you start figuring out something isn't quite right when Vy = level flight.