Then the more advanced course makes more sense; however, I dont consider the first 10 days course vipassana rooted in Buddha's teaching.
I used to do a meditation to cultivate qi. This meditation uses the mind to direct qi to flow from the tip of left hand to the heart then to the tip of right hand. At first you feel nothing, then after few practices you can feel something inside moving in synchronicity with the mind.
I know Taoism through direct experience that mind's intention leads qi movement which leads blood movement.
I thought one was supposed to attain access concentration before doing vipassana; however, Goenka doesnt emphasize that. Only when your mind is agitated he says to do anapanasati to calm down. I would do anapanasati and know my mind is very calm; however, the body scan causes more and more thoughts to arise the more body scans I do in each session.
I followed Buddha's advice that I should know from direct experience if a teaching is true for me or not. After having given body scan 3 months and meditation just got worse, I switched back to anapanasati. I will wait until i attain jhana then switch to do passive vipassana and do both in tandem, using jhana to do vipassana.
For me, the principle is that it has to be passive. During the day I do vipassana. I am always in passive awareness. Every thought affects the body, so when you apply attention to a spot or an area in the body you will induce sensation. You wait for blind spot. You are making active decision if the wait has been long enough or not, and if it is time to go to the next area. However quiet the decision is, it is an activity of the mind which makes the mind active.
When you visit an area that had sensation before, memory can very well induce faux sensation or memorized sensation.
The first insight is to teach the subconscious mind that there is no self. By being aware how things just arise and disappear one learns the first insight. One learns all phenomenon are happening without a self. His first level retreat is teaching equanimity not vipassana. I would have to do many retreats and practice that style to get to his real vipassana retreat.
I am still a preacher for his retreat for non meditators because he makes it possible for people to learn about meditation and cure psychosomatic issues. They can still keep practicing anapanasati.
I consider the body scan more like Qi practice. I can have wave of sensation going up and down my arm by doing body scan on my arm. That is not vipassana. Mental intention induce qi flow. Every night when I sleep I relax my body and when my mind intents to feel certain part of body I can feel energy movement there. It is not vipassana.