Its fairly easy to do once you know how. I do it when I am full throttle and want to shift quick Or jsut accellerating rapidly. It involves a quick momentary release of the throttle just a bit then a nice easy "unclunk" upshift. This is all done at high RPM's ....As far as the clutch going bad...NO...the clutch is not getting used so in fact will last longer..However if not done properly you can ruin some expensive tranny gears
IMO, Honda trannys are clunky whether or not you use the clutch. As for clutchless upshifts, I do it occasionally.