The approach has shown itself historically to be very effective; it also very intensive, however, and, I suspect, requires a certain kind of temperament to pull off effectively. But, then, perhaps that's not surprising.
From some comments by St. John Bosco to his fellow teachers in the Salesian order:
Long experience has taught me that patience is the only remedy for even the worst cases of disobedience and irresponsiveness. Sometimes, after making many patient efforts without obtaining success, I deemed it necessary to resort to severe measures. Yet these never achieved anything, and in the end I always found that charity finally triumphed where severity had met with failure. Charity is the cure-all though it may be slow in affecting its cure.
Remember that education is a difficult art and that God alone is its true master. We will never succeed in it unless he teaches us the way. While depending humbly and entirely on him, we should try with might and main to acquire that moral strength which is a stranger to force and rigor. Let us strive to make ourselves loved, to instill into our children the high ideal of duty and the holy fear of God, and we will soon possess their hearts. Then, with natural ease, they will join us in praising Jesus Christ, our Lord, who is our model, our patron, our exemplar in all things, but especially in the education of the young.