This is just a great wiki article! I must be honest with myself and others. I see myself and some of my behaviors over the years in "Hoovering" and I see how POA has treated me a couple of times in the "Grey Rock" method.
It is important to note the useful quality of the "Grey Rock" method. If you cannot have true NC due to joint custody or some other kind of living arrangement where you cannot avoid a person, using that technique as well as any other method or system of assertive communication will improve your ability to preserve your personal boundaries.