Hey everyone,   I'm curious for those who have personal experience or knowledge about the neidan firing process - focusing on the lower dantian while contracting the lower abdominal muscles and the perineum during inhale to build chi in this dantian, etc.  I'm not sure if it has an actual name or not.  I can find very little on this practice on the internet.   Specifically, I'm curious what the benefits and purpose are both to this practice, and the effects in general in daily life, and whether the practice is really necessary for the rest of the neidan process.   Any idea?   My current twice daily practice is Mantak Chia's version of the microcosmic orbit (focusing on the accupuncture points along the ren and do, one by one).  That's usually it, because the couple of times I've added Zuowang at the end of it, I've had very intense experiences, so I'm somewhat loath to include it as a regular feature. (The first time, I saw what appeared to be a white moon without craters in the darkness, except that it was as bright as the sun.  And the second time, I felt as if my whole body was rising, and then I had very strong experiences of spacial/bodily distortion, and then it felt as if my whole body was sinking.)   Any information on this would be cool.  I learned about the technique from Damo Mitchell's latest neidan book.