"Pulsing" refers to the sensation of pulsing that is often prompted and directed by specific qi gong techniques, as well as by simple awareness and intention.  Michael Winn frequently mentions pulsing as a central principle (see his articles, courses).  Dr. Lin describes orgasm using "resonant wave theory"; different words for the same basic phenomena (see Lin's Links).  Pulses can also be thought of as vibrations (of varying tempos, amplitudes, substrates).  Pulsing is a principle of wide application, that is showing up increasingly in qi gong circles.

pulse rhythmic expansion~contraction

If you look at the above definition of pulsing, pulsing is yin & yang.  Though people often first relate to pulsing as heart-beat only, from a Taoist perspective, everything is pulsing.  Receiving and expending, expanding and contracting.  Cells, heart-beat, the act of breathing, the interaction of heaven and earth, every organ, tissue, bone, (endless list).

Consider pulsing in relation to some pith statements about yin and yang:

            "Yin and yang are rooted in each other.

             Yin and yang may transform into each other.

             When yin and yang separate, essential qi expires."

                        - from the book Statements of Fact in Traditional Chinese Medicine

Pulsing is a concise little package of integral yin~yang.  Pulsing, as a therapeutic tool (when properly used), equally acknowledges both our dense and expansive aspects, and very palpably integrates with the body.  (A very Taoist approach, btw.)

Pulsing and Jing

For now, at least recognize pulsing as a primary characteristic of orgasm, and you might become suspicious that it has some useful applications towards the integration of jing.  Much of pulsing training starts with the pulsing of jing, yet has the opportunity to progress deeply beyond what might be considered jing cultivation.

Jing can be activated through pulsing, and activated does not necessarily include arousal (the male~female desire dynamic).  As always, unaroused techniques form the basis of training.  The following techniques are good for getting started with pulsing in the lower tan tien, each in its own way.  I suggest that you pick one that's more accessible to you and work with it for a while, then shift techniques as you feel the time is right.

        Yi Swallows Chi

        Zang-Fu Pulsing

        Methods and tools of massage that involve tapping or light hitting

        Twiddling thumbs

Though pulsing is often first started through step-by-step technique/s, it often progresses to something that continues spontaneously of its own, as well as something that can be started/augmented through simple awareness and intention.

Sometimes, in the beginning, the pulsing of jing up into the body can be over-whelming.  Also, there is the risk that the sensation of pulsing may seat itself in the chest without sufficient inclusion, integration, of lower energies.  A proper approach towards the rooting of jing solves the potential problems of un-rooted pulsing.

Though the already-noted techniques do emphasize lower tan tien development, once pulsing has started, further rooting of pulsing is desirable.

        The Three Amigos of rooting.

        Pulsing the Joints, Bones

After a While

As the tissues and points of the lower tan tien become clear and activated, you'll find that the energetic center itself has a natural pulsing.  (Note that the development of the deep-center also links to the neutral space, beyond vibration/pulsing.)  Working with a single center progresses to various work with multiple centers.

Give each of these steps as much time as they call for in your own body; I'm painting a broad outline in this essay.

Conclusion

While some benefits are detailed in the linked essays, plenty more goodies await discovery through practice.  Pulsing is intimately connected to some fundamentals.