1. As mentioned in the technique essay, this method was inspired by Michael Winn's article, The Gentle, Easy Way to Pack Your Iron Shirt, specifically his Pulsation Packing method.  As such, Yi Swallows Chi provides many of the same benefits of Pulsation Packing, including the spontaneous prompting of internal breathing.  

With Yi Swallows Chi, the pulsing is created by the alchemical interaction of the swallowed chi with the denser energies within the abdomen.  The pulsing happens quite naturally and spontaneously (though not every time); there is no need to try to get it to happen.  Simply do the practice, and if pulsing occurs - then let it occur.  If not, no worries - things progress, and change, with practice.

2. Promotes foundations for the cauldron.

        - Opens space through the core of the whole torso, particularly in the lower abdomen, and is practice for receiving energy down through the core vessel... All of which is prerequisite for core vessel work, including kan & li.  (As well as being prerequisite, at the same time it is core work.)

        - Ignites consciousness in the lower abdomen.  After some time working with this method, the lower abdomen spontaneously takes a more aware and active role.  

3. This is the most gentle, effective, and profound method of learning to "sink the chi" that I've found to date.

4. Clears heat & stagnation all the way down through the core, including the lower jiao.

         The gentle still holding of the cool external chi allows tension and heat react into, open up, and be relieved, all the way down through the core.  (Emphatic to bring this practice to the full depths of the lower jiao.)

        Relieves stress, internal heat.  We tend to accumulate stress (bound up internal heat) in our bodies during day-time activities of dealing with the world which, if not cleared, inhibit deeply restorative sleep.  There are a number of things that can be done, including moderate aerobic exercise, stretching & breathing (hatha yoga), various circulating, clearing, harmonizing activities - that prepare the way for sleep.  Yi Sw's Chi effectively assists in relieving stress (internal heat) all the way down through the core.

        Re: sexual practices:  Some residual sexual forces often accumulate in the lower abdomen, whether or not you are doing esoteric sexual practices, but especially if you are.  This clogs up the works in the lower abdomen, and can manifest - especially over the long term - as chronic anger, depression, sexual compulsion/addiction.  Though Yi Swallows Chi may not be a comprehensive solution for that potentially complex situation, it is one component: a preventative, and remedial, solution along those lines.

5. By activating the major points in the lower jiao, Yi Swallows Chi greatly enhances the ability of the lower jiao to house, stabilize, and harmonize sexual energy within the lower jiao.

This can really change your experience of cultivating sexual energy.  The lower jiao becomes stronger, harmonized, provides a more stable basis of physical strength, and better fulfills its role of anchoring the fire aspects of the body.

6. If you do expend jing, it gets replenished faster - again, because the points of the lower jiao are activated.  So, whether or not you are taking up long term conservation of jing, this is a practice that is generally healthy for jing.

7. Once sexual energy is harmonized in the lower jiao, it naturally - and very gently - over-flows up into the rest of the body.  (As Michael Winn mentions in his article.)

8. Yi Swallows Chi provides the core aspect of The Fabulous Four harmonious qi gongs.

Training Tips

1. If you have quite a bit of tension in your abdomen, you might find that you have difficulty guiding the chi down very far into the abdomen; you might access & release significant stress my guiding the chi just a little ways down.  That's ok.  Just guide the chi to as far down as you go, and hold it still at that point.  The tension tends to gradually resolve with practice.

2. The technique of Yi Swallows Chi produces unusually profound alchemy by combining the chi from the air plus the denser energies stored in the lower abdomen.  (You'd think that any number of other lower abdominal breathing techniques would do that just as well, but some how Yi Swallows Chi is especially effective... by a wide margin.)  This leads to a couple of useful tips:

        a) The addition of genital massage (un-aroused) prior to Yi Swallows Chi practice increases the alchemy.  It's not a required addition, but an option that you should be aware of.

        b) Following any sort of aroused sexual practice (including dual cultivation) a short session of Yi Swallows Chi (plus massage) can help integrate the forces that tend to accumulate in the lower abdomen.  This is used as a preventative against delayed compulsive desire, nocturnal emission, and general stagnation of energy - disharmonies that often accompany abstention from a normal orgasm.  A few minutes away from your sweet-heart for this purpose, before falling asleep, can help save you from difficulty later.

Further Comments

I find myself more and more inclined to think that the basic strategy of first moving energy out of the lower jiao, and around through the orbit, as a primary method of harmonization... is fundamentally flawed and inadequate.  At least in my own body, the lower jiao:

        a) doesn't get adequately harmonized by that strategy, and

        b) my sexual energy keeps a bit too much of its dense and adamant edge.

The methods that harmonize & stabilize the lower first, before moving up, have - for me - been markedly more effective on both of these counts.  Radical, maybe even blasphemous, I know.  Being true to the experience of my own body, is all.

All this is not to say that Yi Swallows Chi is the only way to harmonize below first, but it's perhaps the most effective that I've found to date.

There are other important effects of Yi Swallows Chi (one of which is profound Earth-integration), as well as variations & progressions on the application; things develop in some very interesting ways.  This practice runs deep: it's fruitful as a sustained main method of inquiry.  I leave it to your explorations.