In any event, Shikantaza is not about that. If you want to pursue that kind of meditation, it is not what we do in Soto Zen. So, I would suggest you need to make your sitting less intense, bring yourself back to the present and to your surroundings more. Even stop counting or following the breath so much, which may be putting you into some hypnotic state (we consider breath counting or following a practice for beginners, just to settle down the mind a bit. It should not be done for more than a few weeks or months, and then turns to balanced, open, aware, objectless sitting focused on everything and nothing).
Some people have attempted to develop techniques to induce OBEs:
* Attempting to fall asleep without losing wakefulness. This method is generally believed to be what causes involuntary OBEs. Inventor Thomas Edison was known to use the sleep state to tackle problems while working on his inventions. He would hold a rock above a metal bucket while sitting in a chair, and let himself fall asleep. This would cause the rock to fall into the bucket and wake him up. Salvador Dali was said to use a very similar method to gain odd visions which inspired his paintings. Deliberately teetering between awake and asleep states is known to cause spontaneous trance episodes at the onset of sleep which are ultimately helpful when attempting to induce an out-of-body experience, as reported by Robert Monroe and Robert Peterson. By moving deeper and deeper into relaxation, one eventually encounters a 'slipping' feeling if the mind is still alert. This slipping is the act of leaving the physical body.
* Deep trance and visualization. The types of visualizations vary; some common imageries used include climbing a rope to "pull out" of one's body, floating out of one's body, getting shot out of a cannon, and other similar approaches. This technique is considered hard to use for people who cannot properly relax. Common sensations can arise such as deep vibrations, impressions of very high heart rate (when it actually is in a relaxed state) and these sensations are likely to cause anxieties. A good example of such a technique consists of the popular "Golden Dawn Body of Light Technique".
* Sensory deprivation or sensory overload. Various techniques aim to cause intense disorientation of the subject by making him lose his space and time references. The first technique, attempting to fall asleep without losing consciousness, can be considered to be a passive form of sensory deprivation. The brain tends to fill in the gaps when there is nothing getting into the senses for some time. Sensory overload consists of the opposite, where the subject can for instance be rocked for a long time in a specially designed cradle, or submit to light forms of torture, to cause the brain to shut itself off from all sensory input. Both conditions tend to cause confusion and this disorientation often permits the subject to experience vivid, ethereal out-of-body experiences. This tends to happen when the subject believes he or she is in a particular position, whereas his or her actual body is either rocking in a cradle actively, or still lying down. Consciousness suddenly transfers to the mental body.