I doubt any spiritual method would pass such a test for that is not its purpose.
Shamanism is a way to understand one's self and the wider world in a spiritual context that allows the practitioner to interact (I believe that you would say perceive to interact) with non-human species, and the environment. This is possible as everything is thought of as alive and sentient. It is a method that has served humankind for tens of thousands of years as a way to care for themselves AND the world around them in a much more holistic manner than our current paradigm.
For me, and many others, that is enough to give it value.