what a coincidence, I was listening to Terrence Mckenna today, he was talking about mixing shrooms with aya. I don't know about it anything myself, but here's roughly what he said:
mixed half dose [2.5g dried] shrooms, half of usual dose of aya.
oh dear. "I thought I've done it this time, folks".
after this experience he said he's very phobic of this mixture, as it effects short therm memory very much in a way that it freaked him out.
this is what I heard in one of his lectures,
hope this helps.