I think most ICs fail because they can. Before we had cars and other decent transportation you had little choice but to stick around in your village and make it work, so villagers figured out how to make it work (or look like it worked). But since we can now move much easier as well as travel farther daily, we no longer
have to rely on our neighbors. That is both good and bad. We have more choices but we have less local social cohesion.
But the place I'm staying at we have a great neighbor who, while he doesn't quite buy into everything we're into, is friendly and helpful and agrees with a lot of our practices.
A lot of it is just about being a good neighbor and being there permanently. If your neighbors know you are good folk that are sticking around, eventually they'll get to know you. I just met a neighbor the other day when they asked us about an egg cache they found that our free ranging chickens gave them

That led to a quick but friendly discussion of the float test - small steps over time will hopefully get them moving more in the right directions.
I should say that I am a participant in the Free State Project as well as a member of a Grange. I don't like the word 'infiltrate' - that is used by those who are opposing us because they fear change. And any political or social changes I'm working towards I am very open about - secrecy is often harmful and sets up conditions that can breed fear. I'm also taking the long view in that I don't expect my neighbors to change their views to be like mine quickly because of my words, but to grow to see the wisdom of it over many years.
That being said, choosing a town in an area that is more inclined towards your views helps. I'm in New Hampshire where the population skews more libertarian. If I was more self-reliantly liberal/green party bent I'd move to Vermont. If I was anti-political and mostly cared about self-reliance I'd tend towards Montana or Wyoming. [This all assumes permaculture being the main goal and being a U.S. person.] I'm sure you can figure out what areas best fit your tendencies, but in any case you'll need to be patient, understanding, and a good helpful neighbor to get what you're looking for.