Is this a workable tip?

I believe Nicklaus said to end a range session on a "high note", so you're on the right track. The problem with the range, or indoor hitting, is the lack of tension and "concern" that creeps in on the course. I cannot count the number of times I would see someone hitting perfect drives on the range, then proceed to top their drive on the 1st tee. Same ball, same club, same flat lie like the range, but then....a top? One would wonder what happened during the 200 foot walking distance from the range to the first tee?

As for hitting 9 shots to get one good one, expect to hit about 1 in 9, or 2 in 9 good nine iron shots on the course, or 11-22% good shots. That means 78-89% of nine iron shots will not be good shots on the course. Plus as iron lofts decrease, so does the percentages of good shots. I personally believe folks should practice using 4 and/or 5 irons on the range such that a 7 or 8 iron looks and feels much easier to hit. I used to hit a blade one irons off the deck for hours, even out of divots such that when I moved to the 7 iron it looked like a sand wedge. I call it "over-club training" (like over-speed training).

Further, going from the range to the course often results in a form of stage fright. It's like someone who can play excellent guitar or piano, by themselves, in their home. But if folks come over, and they ask the person to play the exact same song, they start getting tense because they actually must perform (i.e, people watching on the #1 tee box...top).

Similarly, on the course the mindset is vastly different than on the range. On the course the brain is barking out orders..."don't do this", "remember to do that", "don't look like an idiot and skull this short shot across the green", "don't hit this in the water", etc. The list of "don't do" instructions can become overwhelming to the point of paralysis. Besides, it's more fun on the range because the brain actually takes a break and says "ok, you can have some fun now because it doesn't count". There's no pass / fail on the range. But as soon as someone steps on the #1 tee box, many folk's brains go into uber-instruction mode.

Plus, range surfaces (and mats) are flat which often does not replicate shots on a course, especially out here at PGA West Pete Dye / Nicklaus courses because flat lies are very uncommon. I laugh when I see folks hitting balls on the range, flat lies, then proceed to the TPC Stadium course (Amex Tourney Course) whereby the #1 hole fairway looks like a bunch of small mountains. I wish ranges were undulated to better replicate actual, on course play.

In reality, the percentage of good shots on the range should be about 90% to hopefully have about 50-60% good shots on the course. If someone hits 50% good shots on the range, they should expect about 10-20% good shots on the course due to uneven lies, rough, trees, conditions, wind, then.....tension, concern, etc.

I just read one of the best golf books that talked about practice. As @Tom Saguto mentions. Have a purpose. The author states it as "practice with intent".

I'm all about practicing with a purpose, so if the purpose is some measure of positive mental reinforcement that comes from striping a shot with a particular club and then moving on, then I guess so be it. Is this something I would do personally as my practice routine? Probably not. But that doesn't make it right or wrong. Give it a try and monitor your results. Then you'll have your answer. Having said that - yes, I do much prefer to end a session on a high note with a good shot, so there's that...

@Bazza Clarke Your opening question: Is this a workable tip? IMHO, it depends on what you believe workable means. If it takes 7 swings to hit a 9 iron perfect and you stop swinging the 9 iron as instructed by the tip, then it seems that it is workable. The real question is: if I do this tip, will my ball striking improve?

The answer to that depends on you? Now that you have hit a perfect 9 iron, will you always hit the 9 iron perfect? Probably not, right. But next time you do the tip, maybe it only takes six swings to reach perfection, and so on and so on. If that’s the case, then your ball striking has improved. And you could say this tip worked for you.

But I think the best outcome of this tip is that you will gain some confidence that you can hit a perfect 9 iron. And stopping after hitting the perfect 9 iron allows you to internalize that feeling of success, without losing that brief moment of confidence in yourself by shanking the next one.

Golf is hard, but we love it!