The concept of this routine is invaluable.
The best "lesson" I ever received was from Mike Shannon a hundred years ago when I was in college.
Went to him because I wanted to improve short game.
He watched me hit a few putts, chips, pitches, and bunker shots without comment.
I want instruction! Speak up!
Finally he says, "Here's what I want you to do. Every day, make 50 3footers in a row, 10 6footers in a row. Chip until you hole one. Pitch until you hole one. And then hit bunker shots until you hole one. Come back to me in a week and let's re-evaluate."
He called it a production schedule!
After doing this a while I had more confidence in my short game than ever before. Had a different perspective on the shots, and my scores were much better.
I would recommend, however, tweaking it to fit your needs and time constraints.
Things I learned from it:
It greatly adds purpose and pressure to your practice, which is great.
Hitting putt after putt from same spot is bad on the back and the green.
Confidence soars on the course when you can think,"I made xx in a row" .
When you hit a 100 bunker shots with one goal, to hole it, guess what will be going through your mind when you have a bunker shot during the round?
I prefer shorter goals, done more often.
For short putts, I like to put 4 tees surrounding the hole at 2 ft., 3 ft., and 4 ft. Start by making all 4 2 footers (confidence builder), then 3 ft. and 4 ft.
If you miss start over.
Very simple, but adds the variation of break, keeps you moving, and I can do it once or a dozen times depending on how much practice time I have.
Mix it up.
Have a mini-routine with goals before a round (maybe 3 successful lags, 3 wedges on green, one chip in from as easy a chip as you can find, and three 3 footers in a row.
And have a marathon routine for days you want to push your will to the limit.
One other thing I found important:
once you make a bunker shot, stop. Move on to something else. Leave that image in your mind.
Quoting my Dad, "Never leave the gym unless you've made your last shot."
Achieve and leave!