The ngöndro referred to is the special groundwork or preparation practices -- a set of five practices, each of which is done 100,000 times, or 111,000, or 111,111. (I've never been sure what the right number is but I know it's very important to get it right.)
This set of practices was originally developed as preparation for mahamudra and dzogchen practice, but it has become a kind of rite of passage. Teachers have used it as an indication of a student's seriousness. In the process, however, it became a sort of numbers game.
One practitioner used to visit various teachers. When he asked for instruction, he was invariably told to do a 100,000 prostrations. He had become so used to this request that it took him only ten days to complete the 100,000. Needless to say, he devoted all his time to practice. He didn't have a job. And the physics worked in his favor: it's much easier, mechanically speaking, for a short person to do prostrations than a tall person.
Most people take months, if not years, just to do 100,000 prostrations (which is actually the practice of taking refuge). Then 100,000 repetitions of the bodhisattva vow. Then 100,000 repetitions of the 100-syllable mantra associated with Vajrasattva -- a purification practice. Then 100,000 mandala offerings, symbolic offerings of all the wealth in the universe. And, finally, 100,000 repetitions of a prayer to one's teacher, with the aim of uniting your mind with your teacher's mind.
When they have completed the required number of repetitions, students are deemed ready for instruction in mahamudra or dzogchen and/or empowerment for deity practice. A number of teachers have lowered the numbers to 10,000 of each, but in my experience, students would be better off going the other way -- doing more, not less.
Initially, these were individual practices. Students did them until they had clearly learned something or some change had taken place in them. The teacher of one of my teachers, for instance, at the age of 39 gave up his role as the chief administrator of the monastic estates of a major monastery and went to live in a cave above the main monastery. There he did 100,000 prostrations 44 times, that is, 4,400,000. The numbers didn't mean anything to him. He was taking refuge, praying for refuge, in the way that I described prayer in the recent series of newsletters. That was his practice. Period.
Over time, however, in order to move students through the system (and this goes right back to Buddhism in India), teachers required only that students do a practice until they had certain dreams or visions, and these were taken as indications that the learning had taken place. Then the practices were reduced to a given period of time, or, as became more common, students had to do a certain number of mantras or repetitions to have "done" the practice. The idea, of course, was that some understanding or learning would take place in that period of time or during all those repetitions. Human nature being human nature, however, once the goal was set up, students focused on achieving the goal and the learning became secondary, or ignored completely.
Many people now complete the required number and say that they have "done" ngöndro, but it is not clear what they learn in the process.
What to do?
For these reasons, when students requested to do ngöndro with me, I made it very clear that they would never be able to say that they had finished or completed it. They would start with refuge (prostrations) and do that as their practice. They would check in with me periodically, and when some real understanding or learning had arisen, then they would move to the next practice. Needless to say, very few students practiced ngöndro with me.
All in all, I think there is too much weight put on teachers. Learning is what is important. Learning can and does take place without teaching, in many different areas, from athletics to chess, from cooking to mathematics. A teacher can greatly facilitate, enhance and/or deepen learning, no doubt, but we all know from our educational experience that teaching can take place without any learning necessarily happening.
Many kinds of learning cannot be taught. Ngöndro is really about those kinds of learning -- things that can be learned only through your own experience, only through the experience of doing without goals or milestones or markers of achievement of any kind. Through these practices, you may learn what faith, commitment and devotion actually mean for you. That cannot be learned from a teacher or anyone else. That is why it is an important preparation for other forms of meditation. And that is why you never finish ngöndro, because there is always more to learn about faith, commitment and devotion.