I've been looking up "entheogen" since you mentioned it. I've never heard the word before. However, I wonder if there is evidence that entheogens provide changes to the brain as some claim meditation techniques provide:
http://io9.com/how-meditation-change...el-b-470030863
I can see how meditation might help with creativity, but entheogens make me suspicious. I'm not against using them. I just don't see the connection between them and creativity. There is a belief that artists live an odd sort of life, but if one breaks out of that idea and considers art as just a job some people engage in, and creativity something that even equity and bond traders have, one might be closer to the truth.