Your instructor's method is the usual--I've done it myself on a scale model where choking is difficult. On most engines in use today there is no reason not to.

But the FPs do not have ball bearings, so when you push the charger against the spinner you're grinding metal between the drive washer and the the crankcase--take a look--you'll see a little grey sludge after a difficult start. It's not an issue in the short run, but eventually that can take off enough metal to cause the crank pin to start hitting the inside of the back plate. And then, as you mentioned, there's the wear on the spinner.

Give the hand starting a try--it's exciting to get an engine going that way. For years I didn't even own a starter--I had the lightest field box in the club. Jim