Fascinating ways to confuse your brain and create hallucinations.
The natural ability of humans to hallucinate is a fascinating field of study. Hallucination and imagination and visualization can all be used to stimulate altered perceptions, altered states of consciousness, and also out of body experience (OBE). Anything that shifts the perceptual center of conscious awareness outside the physical body can trigger an OBE. This can also be done through disorientation, e.g., the witches cradle.
See Witches Cradle for further explanation and videos on this method of generating hallucinations and out of body experiences.
Thogal is an ancient Tibetan practice. There are very few books containing information on this.