Let’s feed the herd with convenient crap between inhaling and exhaling. So their reptilian brains have enough stimuli to process. If it is done frequently and multichannelly enough their other brain functions deteriorate to a point of becoming uncomfortable to use. Once comfortable being stripped down to a lizzard with no mind of their own you got yourself an army of half creatures hungry for some more crap unquestioned anymore.
So you provide them with their warm meal of brownish color in an appropriate package and make them dependant. Not only they eat shit, they are repulsed by normal human food. Books.
Warm meal guys, let them feel secure. That’s the way you do it, money for nothing.