Just looking at it on paper I can kinda see the idea of it.
There are variant schools of thought, so which paper were you looking at?
The union of the sexes to produce wish fulfillment via orgasmic release is a typical formula. In terms of Paschal Beverly Randolph, this is the only proper formula, but it should only be done after fasting, prayer and other observances, and only between man and wife under certain astrological conditions on a Tuesday during a full moon and for no more than half an hour.
There are formulas of onanism which some think to be highly effective - for example, Naglowska's "white charger" concept, in which the male, after proper preparation, must withhold his emission during coitus as an act of overcoming. This example is rooted in her conception of "God=Life" and "Satan=Death". That is, the free flow of energy in the cosmos, reflected in our flesh, is represented by God as all giving, and the contrary force of Satan is the restriction of this energy for the purpose of self control and domination of the instincts. This is why she was improperly called a "satanist". For Naglowska. the "white charger" symbol is a horse that must be tamed. So virile magus + beautiful priestess - orgasm = magical self transformation, at least for the male. This is a precursor to other powers.
Crowley is usually the main source of modern conceptions and practices as I understand them. He blended a sort of Freudian-Nietzschean perspective of magic with Tantrism. He was a anti-onanist to the extreme. Orgasm is not just a key to power but also an obligation as typified by passages in Liber Legis. Also, any concept of "love" as we understand in the romantic sense is useless here. By his own admission he pretty much experimented with every conceivable and inconceivable technique, with everything and everyone, though the main aim seems to have been for visionary purposes. I think during the Paris Working he was trying to get money, but this action was probably more reflective of an actually experiment to determine formulas for future workings. If one can comb through his euphemisms one can glean useful perspectives on the psychosexual interpretation of magic (or Magick).
Grant builds on Crowley's (and others, such Spare, Parsons, etc) conceptions and reports in a variety of ways which seem to translate pretty much all magic into sex magic, from before the beginning of recorded history. It's all apocalyptic in a sort of Lovecraftian alien invasion sense and I find it inspiring, actually.
There is of course the God and Goddess rites of Wicca and such, these all being (argumentatively) rooted in Crowley to some degree, though there are questions of deeper history. Witchcraft, as the medieval "Christian nightmare" bears little resemblance to what covens do today.
Ancient Gnostic practices and/or accusations against them can kind of give an idea of the origin of that nightmare, as there is a good deal of erotic imagery embedded in some texts. But it's hard to sort out what they actually did vs. what is projected on them. For example, the parable that the Soul is female and oppressed until she learns to wear her genitals on the outside may be a confusing image to some people. It makes good for arguments against heresy on some pulpits.
It is probably helpful to actually get a perspective on actual Tantrism and its influence in the West since the 19th century as a base of comparison between different doctrines. Once commenter on "Western Tantra" pointed out that, due to an inherent mercantile greed for satisfaction - which is the great flaw of many people's approach to sexual magic and mysticism - there seems to be a confusion between "sexualized ritual" and "ritualized sex".
As to personal experience all I can say is that Randolph's methods do NOT work for me. Naglowska's is a philosophical petticoat, and Crowley's a menagerie of "dissolution" which nevertheless holds a decent cosmic perspective that is useful in certain applications. I tend toward an ecstatic and poetic interpretation of magic in general, though with an attitude and goal of detachment and objective indifference. Like any other form of energy, the libidinal force is just a tool for work. But it arguably the most powerful of all powers, if not the singular power in itself manifesting in deceptive veils under every other magical technique, no matter how drab and mundane they may seem. Love is the power of becoming, generation the manifest act of creation, and "Love under Will" is an ethic of conjuration.
When I said, "LOOKING AT IT ON PAPER;" That was simply a Metaphor so to speak. I have a general idea about how many types of magick work. So when you look at , "Sex Magick ;" I start to assume it would work similarly to say Chaos Magick. There's lots of energy that is being produced so I assumed that would be a good place to start.
