A very cogent point, and one I took too lightly. I do see two causes for hope:

1. You have Mad Oratory Skills, and so have some scope to set fashions of behavior.
2. News travels slowly, so you can field-test your approach in small communities before the big show.

It might be smart to start in another country, so that none of your eventual targets see you make your newbie mistakes. It's not as good as being born in Egypt/Judea/wherever, but as you point out that's really hard to fake.