If a chemical alters perception, that just shows that consciousness is strongly affected by the material, but other non-contradictory hypotheses aren't thus disproven.
However, I am unsure what good evidence for a corresponding immaterial part might look like.
I think a better approach is philosophical, by considering the nature of thought and the spoken word.
In the same way, if this is a dream of sorts, the fact that certain dream behaviors can trigger certain changes in experience is also internally consistent. Of course, this "dream" has much greater stability to it, but the basic idea holds.
There is complex physiology going on producing a consciousness (so it seems to me) that can be altered when that physiology is altered. We can see at least some of this physiology. Suggesting all that physiology in our world is actually happening in the dream world of some other being doesn't seem very interesting as it still leaves us here in the same material (as we can measure it) reality that science is... still pretty damn good at describing. So why even bring it up? If there's evidence that points us that way, cool, otherwise, Occam's razor seems better.
https://maps.org/2004/08/08/nobel-prize-genius-crick-was-hig...
Simple put, psychedelics are used throughout the animal kingdom by all species for this same type of enlightnement. Arguments can be made that mushrooms brought about human evolution by waking us up to our own conciseness. We are the first generation of people to be tainted by the War On Drugs. And we will be the last to have forgotten it.
https://www.inverse.com/article/34186-stoned-ape-hypothesis
https://www.smithsonianmag.com/smart-news/dolphins-seem-to-u...
Unfortunately, our generation has grown up being fed properganda about how Drugs are bad and religious is the saviour and the only pure way to live.
https://en.wikipedia.org/wiki/Caesar%27s_Messiah
One just needs to look at MDMAs effectiveness on treating PSTD with Gods version of treatment that covers up the trauma with religion instead of unwinding it from the mind.
https://adf.org.au/insights/mdma-ptsd/ Source from gods chrous themselves where they claim MDMA and ecstasy arn't the same thing now because science is showing its "positive uses" - even though every "Just Say No" ad i saw as a child insisted they were both going to fry my brain into an egg.
These substances will not produce profound effects when taken recreationally - no healer from any aboriginal culture will claim that. They are to be taken with intent, with specific settings under specific conditions in a variety of doses for you to gain a better understand of oneself.
This claim, at the very least, is false.
I do think there are rational realizations that rational people can come to under the influence of psychedelics, that they might not otherwise, though.