It is said that DMT (Dimethyltryptamine) which is produced in the pineal gland is the key to the mysteries of the afterlife. When we dream, the scenes and visions are a product of this chemical. It is abundant in many common grasses and plants which can be easily converted in a form that you can smoke or drink as a potion called Ayahuasca. Drinking this potion is the traditional way of ingestion by the Shamans in South America.
In this video Joe Rogan talks briefly about this wonderful compound which is considered the gateway to the many dimensions of the afterlife. You can learn more by searching the internet or by clicking the link below.