This excerpt is from Sexual Energy Ecstasy: A Practical Guide to Lovemaking Secrets of the East and West by David and Ellen Ramsdale (pp. 304-307)
The late Rudolf von Urban, M.D., prominent psychiatrist and [author of Sex Perfection and Marital Happiness], devised his own approach to making maximum use of the subtle sexual energies. He made a number of claims for his technique based upon the physical, emotional and mental benefits he observed in his patients who used his "bio-electric" method of intercourse. We will call his method Bio-Electric Sex.
For example, von Urban reported that health problems as diverse as high blood pressure, skin disease and sleeplessness were totally cured in some patients after just a couple of weeks of Bio-Electric Sex. He also reported that the technique was found to be extraordinarily relaxing.
Von Urban writes that some experienced renewal of their marriages. Those who were in love became even more so. Some long-term relationships that had been full of discontent suddenly enjoyed peace. 
Some lovers shared a special ecstasy during the Bio-Electric Sex sessions. Van Urban realized that something very valuable and wonderful was taking place. Beyond any immediate personal pleasures a man and woman might experience with this technique, startling benefits were being experienced by some participants that they had not enjoyed with conventional hot, hard style intercourse-to-orgasm.
At some point, von Urban developed a theory to explain these effects. Von Urban had worked out his theory and was prescribing this technique to patients as early as the 1920s in the United States.
In brief, von Urban's theory was that the cells of the male body-mind and the female body-mind are of opposite electrical polarity. Via prolonged contact of the skin, particularly between the moist areas of the body, ie., the genitals, the bio-electric quality of the skin changed.
This change in the skin attracted the unique bio-energy in the cells of the male and female forms to the surface, where they could be exchanged, resulting in benefits and perhaps ecstatic experiences.
Today science has confirmed the electromagnetic character of the human body-mind as a whole and of the human skin in particular. Von Urban's notion of male and female electrical cell polarities will remain a mystical non-explanation until it is studied scientifically. However, his intuition that the best scientific explanation of this process would be in terms of human bio-electromagnetism is remarkably contemporary.
Von Urban also explored the issue of contraception from his bio-electric point of view. He believed that barrier contraceptives made of rubber (an electrical insulator) such as diaphragms, cervical caps and condoms, block the energy exchange at the genital juncture. Technically, Van Urban was probably right. But emotional and psychological resistances create much more significant barriers. Your openness and high energy level easily overcome this technical obstacle.
Von Urban gave precise, easy to follow instructions: Take a shower or bath.
Completely naked, cuddle, kiss and otherwise turn each other on.
Adopt the Scissors position with the man on his left side. With or without an erection, his penis is placed just inside the outer lips of her vagina.
Lie in this way for at least 30 minutes. Focus intensely on any genital feelings. Keep attention on the exchange of male and female polarized energies taking place at the genitals.
After the 30 minutes is up, have regular intercourse with genital thrusting but stay in the Scissors position. This should also last for 30 minutes. Male ejaculation is to be avoided. (Note: von Urban said nothing about ejaculation after the second half hour was over.)
Should male ejaculation occur, the couple stays genitally fused for 30 more minutes from that point. This is to insure that the bio-electric interchange between the lovers is complete.
The beauty of von Urban's approach is it proves that knowledge of or belief in Eastern mystical concepts is not a requirement for success with Tantric sex. His emphasis on the practical value of Tantric lovemaking techniques is quite appropriate. The most important thing, as we have tried to say many times in many ways, is to just simply do it. Take the leap of faith and try a technique such as Bio-Electric Sex.
Granted, it is a formula, and that will turn some people off. What we are dealing with here is the art of synchronizing energy. There must be some method to your development, at least in the beginning. Ideally, you will unite in a style such as this - energy, not performance, oriented - at least once or twice a month, perhaps on the new and full moons.
If you analyze or question it, you may never do it. Just take our word for it and try it for three months. That's only six sessions. Based on our experience and the feedback from our students, you should see definite practical benefits, such as greater relationship harmony. 
With no more effort or thought on the matter than this, you will see positive changes. Even issues that seem totally unrelated to sex and intimacy, such as finances or health, may improve, as doing Tantra intensifies and balances your energy fields. This is very powerful stuff, and the role your conscious mind plays can be quite minimal.
Tantric sexual loving works in mysterious ways. The deep, inner satisfaction the woman seeks through love is achieved internally by these methods in a way that conventional lovemaking styles, no matter how affectionately performed, rarely match. Paradoxically, some couples find that, regardless of the man's skills as a lover, his most satisfying performance for her takes place when they are genitally united and he does absolutely nothing!
Doing Tantra together is the best way to insure a deep, lasting, faithful relationship. Often, the woman must initiate the Tantric unions, at least at first….. Once he sees the results, though, he will look forward eagerly to the next time. If he is resistant at first, point out that doing Tantra is relaxing and reduces stress.
A writer acquaintance of ours and his wife have followed von Urban's instructions to the letter for many years. Over breakfast one morning, he described their experience with the method as "the Orgasm beyond the orgasm, the High beyond the high."