For those of you who are not called to do plant medicine I suggest this as an alternative. There are several people trained in this methodology that was developed by Stanislav Grof. He was doing research with psychedelics (particularly LSD) up to 1064 when it became a schedule one substance and therefore illegal. You can most likely find someone nearby who is trained in this type of Breathwork by going to Holotropic.com.
By doing conscious connected breathing for anywhere from one to three hours (!), meaning no pause between exhaling and inhaling, you move into an altered state where healing and revelations can occur. I was trained in a similar model in the mid 90’s and introduced to Holotropic Breathwork about six years and can attest to its efficacy. Try it out for yourself and see!