In Halloween 3: Season of the Witch, isn't Cochran's plan pretty flawed? He explains that he's using the masks and stone from Stonehenge to kill children across the country in some sort of pagan sacrifice. What he will gain from doing this is never really specified. Will he get power? Will the pagan Gods do something for him? It never says. Anyway...
The real issue with this is that not everyone in the country is going to come into contact with one of those masks. Eventually, the people who survive are going to be able to trace the deaths back to him. Now, he does tell Challis that it will be a different world after this event. What he means by that is, again, never explained. Will he have the power to enslave or kill those who don't die from the masks? We don't know.
Essentially he's just going to kill a bunch of children, and while no one may be able to explain the magical elements of the deaths (the snakes and bugs).... it would very likely end up being viewed as some kind of factory error with the masks.