A brew with Syrian Rue instead of Banisteriopsis Caapi (Ayahuasca) vine is not really Ayahuasca, but rather an Ayahuasca analogue. The Rue/Mimosa combination can be very powerful. The difference is -- when you talk about communicating with entities, B. Caapi vine IS an entity who cares about what is happening to you and tries to take care of you on the journey. If you use Rue instead of Caapi, you are sort of on your own, as Rue doesn't really care what happens to you.
There is a lot of info at
www.ayahuasca.com . Including a whole forum.
Learn about the dietary restrictions! There are restrictions that have to do with physical safety, and restrictions traditionally used by the Indians that have to do with spiritual balance and sensitivity.