If the possibility of spirit journeys and visions of supernatural creatures is of interest, I recommend The Carlos Castaneda series. In the first book , Teachings of Don Juan the author goes on psychotropic trips and meets spirit creatures. He analyzes his experiences using anthropology. The scene where he meets Mescalito is memorable in its weirdness. My favorite, though, is when he meets his spirit animal in the 4th book. I think about that all the time.
Castaneda makes clear that the drug itself is just the trigger to cross into non-ordinary reality. His spirit guide the brujo Don Juan does a lot of subtle preparation to make sure that these trips are not random or scary. He prepares expectations in advance through discussion, makes clear what is to happen, and then afterwards there is a debriefing of sort to categorized and move into normal memory the experiences Castaneda has in non-ordinary reality.
So too the vision you wish to produce. It cannot simply be a drug in a bottle and produce a uniform result. You need spirit guides and a uniformity of culture. If there is a culture surrounding the use of this drug and what one can expect to find in the non-ordinary reality it produces, this could produce the homogeneity of experience you are looking for. A culture of people who share their experiences will help reinforce this - it becomes a religion, one component of which is the partaking of this drug. There is much precedent for real life religions that have components of vision quests and hallucinatory experiences.
People visit Mescalito because he can be helpful under the right circumstances. Why exactly anyone would wish to visit your many eyed god is, I suppose, what your story will be about.