Updated: Jul 27, 2018
It's an interesting article in Wikipedia.
Ego death or ego-loss refers usually to temporary loss of sense of self. This may happen due to use of psychodelics like Ayahuasca, DMT, LSD, mescaline, peyote, psilocybin etc. The same concept is also used in modern spirituality and it may correlate to some easten religions to describe a loss of attachment to a separate sense of self and self-centeredness.
This conception is an influential part of many teachings, where Ego is viewed as an accumulation of thoughts and feelings, which creates the idea of being a separate entity. In the Buddhist meaning one can truly be free from suffering only by disidentifying one's concsciousness from it.
That's all very true. If ego becomes less important, if ego is diminished, one can see clearer, think more precisely etc. As it said in the book:
Forget your ego, your self, let them go. You don’t need them. No one can hurt you in any way, and you don’t have to affect anyone in any way.
There is another interesting article on the same subject. An entheogen is something which can induce certain spiritual experience aimed at development or achieving transcendence, including not only drugs but also divinatory, meditation, yoga, prayer, trance, rituals, chanting etc. It's all very interesting and promising, indeed.
The problem arises from another passage in the first mentioned Wikipedia's article concerning on John Lennon. He was strongly affected by the psychedelic experience books and took about a thousand acid-trips, but it only exacerbated his personal problems and difficulties.
How it can be? Are the psychodelics worthless? The wise answer is coming from Alan Watts:
I shall make it clear that psychedelic experience is only a glimpse of genuine mystical insight, but a glimpse which can be matured and deepened by the various ways of meditation in which drugs are no longer necessary or useful.
When you get the message, hang up the phone. For psychedelic drugs are simply instruments, like microscopes, telescopes, and telephones. The biologist does not sit with eye permanently glued to the microscope; he goes away and works on what he has seen.
There is no difference in principle between sharpening perception with an external instrument, such as a microscope, and sharpening it with an internal instrument, such as one of these [psychedelic] drugs.
Strictly speaking, these drugs do not impart wisdom at all, any more than the microscope alone gives knowledge. They provide the raw materials of wisdom, and are useful to the extent that the individual can integrate what they reveal into the whole pattern of his behavior and the whole system of his knowledge.
Conclusion: use tools as tools, as they are just tools, instruments. The experiences during the psychical trips or views from the microscope seem to be very real because they are real. Good to know this reality, indeed. But 'the biologist does not sit with eye permanently glued to the microscope; he goes away and works on what he has seen'.
There is no need to take a thousand acid-trips. It didn't help Lennon and it can not help anyone.
Meditation or yoga are also tools. By the way, the ego itself is a tool. As it said in the book:
This anchor, this self-censorship, this confidence, this egotism, as some might say, is needed. It holds life and helps us live, it helps us to cope, to act and to achieve.