I can't quote you any studies, but I can tell you that from experience, ayahuasca (and many other natural psychedelics) help/make me hydrate more, sometimes a LOT more. If you've salted your system a lot beforehand, it might make this experience stressful.
Good hydration=health. I'm not sure salt would affect the experience negatively, especially psychologically, but I believe that it would help give a more "clear" experience.
I think a lot of the dieta recommendations don't come from a place of "it's dangerous." I think that's a common misconception, especially here on the nexus. I think those recommendations are more to help make the experience clearer and smoother, and actually are largely directed toward
patients who are in need of healing on all levels (hence the dieta) and not just looking for a spiritual experience.
From the unspoken
Grows the once broken