Yes and no.
Yes they deliberately use psychological manipulation. Why do I say this? Look at the BE book that was used in the theocratic ministry school. Look at the many speech counsels that are used in there that involve psychological tactics of persuasion. Look at the use of images and drawings in the literature and the great attention to detail that go into them. Look at how these images are designed to appeal to the emotions and reinforce stereotypes about worldly people. It is very plain to see that much deliberate effort goes into brainwashing rank and file JWs.
However, the leadership does not consider their psychologically manipulative tactics as being nefarious or unethical. They are not using these tactics with the guilt and knowledge that they are using unethical cult tactics. In their own minds, they are just using very effective methods of reaching the hearts of people. If it is pointed out to them that their methods amount to brainwashing then they dismiss the claim as being nothing more than hateful rhetoric by worldly opposers and apostates. They will even say that the members minds are washed clean of the satanic filth of the world. See Samuel Herd's first hosting of JW broadcasting, as an example of this. Call them a cult and they say Jesus' followers were labeled as a sect.
So I believe they are deliberately using tactics of manipulation, but without realizing that these tactics are actually unethical cult tactics. They have convinced themselves that they are very effective teachers using very effective methods of persuasion and reaching the heart. If it is pointed out to them that they are using unethical cult practices then they go into denial and say that they're being maligned just as first century christians were maligned.