This is a unique thought on the topic of mind control.

New Scientist Breaking News - Parasites brainwash grasshoppers into death dive

There was a SciFi series a few years ago where aliens hired human helpers and implanted them with an "enhancement" chip in their brains.
The chip also include a "Motivational Imperative"  as part of its programming.

The Motivational Imperative ensured that the human helpers would always have the safety of the alien as their HIGHEST priority.

Post hypnotic suggestions can do well for specific behaviors, but a motivational imperative is would have to affect the subject at the level of beliefs, values and even at the level of identity. In other words everthing they believe, all of their values and even who they think they are is linked to this motivational imperative.

So, can a motivational imperative be "implanted" into a subjects mind? If not with a chip then can the subject be programmed to hold one value higher than anything else?

The answer to that is that we already are doing it. We have institutional religions that have done it for centuries.

While the brainwashing/Mind Control of traditional religious institutions lack quality control I think they are on the right track to making a consistent process that implants a "motivational imperative".

As a speculation what could these traditional institution do to command huge LOVE (not fear) within the individual?

1) Supply their needs in mystical ways. "You worship the God that feeds you."

2) Reveal valuable and important insights to the individual about themselves.

3) Never punish wrong action of the individual, only show extreme sadness, i.e. "...God wept." This would not imply shame/guilt but make it easy for the individual to infer it.

4) Make all access to "higher levels" of learning and service forbidden to many. Because people want to know what they aren't supposed to know it would motivate without fear/guilt/shame. It also allows the institution to qualify any applicants for the most suited and properly train/indoctrinate/program/brainwash them every step of the way.

5) Offer a "Rumspringa". Rumspringa, an Amish rite of passage, the individual around age 16, is offered and even encouraged to leave the community to explore the world outside the very restrictive Amish culture. Thus after a thorough lifetime of indoctrination into the Amish culture it is taken away from them.  There are no restrictions to what they can do during Rumspringa and sex, parties and drugs surprise no one. The only caveat is that if they choose to return to the Amish life they must choose to do so for life. The result is that after leaving the security of the Amish community and entering the indulgences of the The World 90% of all those to take Rumsprina return. "Rumspringa" helps create the illusion of choice... but their final choice is one of an adult... a choice to return and never leave again.

The combination of 1) and 3) will tightly bind the individual to the institution and 5) allows the individual the illusion on free will.

Now these are the ways to create a motivational imperative covertly, by setting up an enviornment. The overt ways of doing it are more obvious

1) Make is law. "My wants, whims and desires are your NEEDS."

2) Use heavy guilt to induce conformity.

3) Ritual enactments of the benefits of perfect behavior and the punishment of disobedience.

4) Offer debates on how to best follow the motivational imperative. (Notice that the debates aren't on wheather to follow the MI, but how best to follow it.)

Okay, so it's a long way off before the motivational imperative brain chip but it's already being done on an institutional level with varied degrees of success.
Good luck.