It's probably not ethical. How repeatable it is is for an experiment to decide, if it was possible to arrange ethically.
Ethics are just someone else’s opinion.
Something isn’t ethical or unethical, somebody just doesn’t like it. They might have a reason for it at best.
What's unethical about it? It sounds the locals consume it anyway. If the experiment is blind you can even tell the participants what is it about beforehand without losing too much validity.