There are two main branches of tantrism: physical tantrism and mental tantrism.
Only mental tantrism is initiatory, it consists in transforming sexual energy into mental energy.
Various traditional techniques produce this result. For example, indian yogis visualize a goddess (or Shakti) dancing in rotation on one of their chakras (women can of course use a male image). Through concentrating like this on godesses, they end up making love to them in the astral plane in ecstatic experiences during the night.
This principle of transformation of erotic thoughts into energy can also be found with european nuns who, through concentrating on Jesus Christ, end up having sexual experiences with his image in the astral plane. The most famous example is Saint Theresa of Avila and her highly erotic ecstasies.
An efficient way to practice this type of exercise consists in mixing an erotic thought or a fantasy with a phosphene. The phosphenes are all the subjective sensations of light, i.e. those which are not directly produced by light stimulating the retina. They can be produced by short periods of focusing on sources of light.
Do a phosphene.
Visualize a dot of light whirling between the mental image of a fantasy and yourself.
Repeat this exercise several days in a row.
You will experience making love in the astral plane.
The connection between sexual energy and spiritual energy appears clearly in this pertinent comment by Doctor Lefebure:
‟An astronaut that would travel towards the sun will first see its light above him. After passing the point where the gravity of the earth and the gravity of the sun cancel each other, he will perceive the light of the sun coming from below him. Similarly, in the beginning of spiritual elevation, sexual forces seem to be opposite to spiritual light but, after a certain level of elevation, the mystic realizes that it thanks to these sexual forces (transmuted through exercises of rhythmo-phosphenism) that he/she reaches the greatest illumination.”
Extract from From the Praying Wheel to the Spiritual Dynamo.
The principle of using phospenes to transform the energy of light into mental energy was discovered by a French physician and scientist, Doctor Francis Lefebure. Thanks to the phosphenes, he designed several cerebral activation devices. One of these devices can be combined with the pratice of tantrism: the Gyrascope.
Indeed, tantrism can lead to sexual deviance. Practicing with the Gyrascope purifies thoughts and helps avoiding these problems.
The effects of the Gyrascope can be compared to the effects of a centrifuge. For example, when blood is centrifugated, the heavier elements are pushed towards the periphery bu the centrifugal force. As a reaction, the lighter elements (pure water in this case) are concentrated around the central axis of rotation.
The effect of the Gyrascope on consciouness is the same: the heavier thoughts will be swept out of the consciousness of the individual, producing a genuine purification of thoughts, a token of sanity.
Phosphenism © Excerpt from ‟Phosphenic Energy Universe”.