Hey there

Long story short, I see aya primarily as the Master plant, so I go the ceremony way.
There was an aya retreat in Europe this summer, organized by a friend of a friend, with a Shipibo shaman of very good reputation. Unfortunately, with aya being illegal in that country, the many obstacles they faced led to many compromises, with the result of nobody getting any visions.
The first night was my first. I felt pretty ready to meet both angels and monsters. Sitting there in lotos, with bucket ready, it surprised me that instead of howling, crying or purging sounds I only heard some snoring, about half an hour after the drink. And that was pretty much it. First I thought, ok, maybe I'm not sensitive enough, bla bla. But later I found out that it was pretty much the same (nothing) for everyone else in the group, for the whole week.
Well, I did get some vivid mental images in meditations, as I usually do, but from aya I expected more, due to her reputation

After about 4 nights of costly nothing, my friend told the shaman that it feels a little bit like emperor's new clothes, and why is this. The shaman reluctantly admitted that 1) we're running out of chacruna, so there's hardly any in the brew, and 2) he had to prepare aya and chacruna brews separately, which is not the way to do it, and he can see how it affects the potency, despite all his magic. He reassured us that healing still occurs on many levels, just without the cinema. Maybe the good fellow was right? He seemed to be more shocked about it than we were. Still an enjoyable week though.
Now I found out I can order aya online, so I did. The vine, chacruna, agua florida. I'm gonna brew it myself, shaman style, London version

I think I have the cooking part covered (at least in theory), will have to read more about DIY exorcism etc

Anyway, thanks for all the info I found here.