Hawkins told me that if a Sea Org member sought outside help he would be punished, either by being declared a Suppressive Person or by being sent off to domanuallabor, as Hawkins was made to do after Miscavige beat him.
In addition, with modern technologies and the emphasis on information as a method of currency, people can work in information and knowledge jobs much longer than they could in factory or other manuallabor jobs, and can do so from their homes.
And since educated immigrants are less likely to fill low-paying manuallabor jobs, a demand for illegal immigrants willing to do that work would be created.