Have read a bit about it - have a book about it and used to ride the "Shaman's Chariot".
Wouldn't recommend it myself, as it means actively opening yourself up to "spirit guides".
Surrounding the activities of this belief system & ritual way of life are some rather respectful ways towards the earth and towards each other. So within the midst of the spirits are truths. But of course there is often a turd in the mix when it comes to most world religions. Here the turds are the spirit guides. Some would reason these guides appear as a result of taking potent amounts of hallucinogens and the end result being manifestations born out of a chemical trip. I am not so sure though.
David Icke last year took a trip on the Shaman's Chariot and wound up writing an entire book as a spin off with his experience with "the great universal spirit".
False prophets pop up everywhere nowadays and often find inspiration from the other side.