Presumably the San spread their worldview and cosmological ideas throughout Asia; however, prior to this, they had already done so throughout Afrika, as paleoanthropological information indicates that at one time the entire continent was share between them and the Mbuti. Furthermore, the San along with the Mbuti, Hadza, and Sandawe, have the oldest DNA on planet earth. Thus, the San more than likely transmitted their knowledge and techniques to other Afrikan peoples, the Kemeyu being one of them, and this is consistent with the concept of cultural evolution that I present in my book, Distorted Truths. In Kemet (Egypt), this energy was called Sa, which resided in the body in the umbilical plexus. As Sa orbited the body making its way up the spine and then down the front, the Kemeyu likened its movement to the orbit of the sun (Ra). Stirred by passion/emotion Sa (vital essence) travels from the umbilical plexus and pancreas gland to the gonads, where it moves up the spine to the crown plexus. Once it reached the pineal gland, it gave birth to the spiritually mature person. This knowledge of the inner vitality/sexual energy is widespread in Afrika. We confuse matters when we limit its use only to intercourse, which is often the perception one gets from “sexual” yogas. But the San explain that the primary use of this energy is ritual and communal healing but it is also capable of being generated during intercourse. So in fact, this is the same the energy every Afrikan society uses for ritual purposes. It is only in less communally oriented cultures that this energy is use exclusively for private purposes, whereas in Afrika there is no separation between the two. Now we can understand why many Afrikan rituals require ritual abstinence before a communal hunt and the diviner who performs the hunting rite must be celibate for weeks before the hunt. In this case, the entire society harnesses inner vitality/sexual energy and especially by the person who acts as the intermediary between the spiritual and humans realms. This example can be replicated all over the continent.
Not all San know how to experience Kia (trance) during sexual intercourse, only experienced healers and elders possess such abilities (even in China, they did not teach Taoists sexual techniques until after one reached forty), which is another example of how knowledge is age specific; sexual knowledge is age dependent like everything else in Afrika. With maturation the person learns to discipline himself and integrate the various aspect of the soul; sexual discipline is part of the process and through disciplining sexual energy one can learn to discipline the soul(s). Afrikan societies expect elders to possess wisdom and to be exemplar of calm repose. In contrast is the younger person that is impulsive, noisy and lacks self-mastery. Both behaviors have a sexual corollaries: the former person lack self and sexual discipline, thus he must grow to learn the importance of sexual economy; while the latter is measured and disciplined; the person who has tamed his animality and is a master of his sexuality. Systems of sexual yoga teach sexual conservationism (semen retention), something certainly needed in polygyny, but something even more important to an elder because of its practicality. For the elder, the more energy one conserves the more energy one has, so sexual conservationism has a direct impact on their quality of life. Sexual energy which is a powerful creative force, when conserved and properly utilized offers tremendous (psychic) possibilities for the person. However, when a society has learned to harness this energy it can become a "civilization" or more properly, a high culture.
P.S. Now you can see why the West has never had a civilization as they had always lived in the midst of sexual madness.