I would consider any of that author's advice with caution.
Hendrix started his own brand of MC, Imago Therapy. Our "relationship counselor" before we married was certified in it. Following Hendrix's approach to relationship dynamics, our counselor chose to overlook major red flags in my then-BF, because she was so wedded to the idea behind Imago, that somehow we "chose each other" out of our wounded pasts, primarily our FOO. So she "had to" see us work it out! Very Freudian. We saw her because I was having major doubts about continuing to date him; I wouldn't have gone ahead with the marriage feeling safe, had she not used this Imago Therapy stuff to assure both of us "we were destined!"
You cannot trust a method of relationship counseling that depends so heavily on people being revealing and honest about their past, as is needed to do Imago Relationship Therapy.
Looking back, it is not surprising that we lasted only 4 years at most before he cheated; he had totally fabricated his FOO story, which I suspected but the counselor apparently dismissed. I went back to college to major in psychology, as I felt betrayed by that counseling, as well as by the man I married! I wanted to know what sort of psychology "wisdom" could help me deal with the trauma of such betrayals.
So I searched in counseling textbooks and online research databases, but never found any references citing Hendrix as an author, nor anything about his Imago Therapy.
That told me that as of 2008, Hendrix's pop psychology approach had not undergone evidence-based, peer-reviewed research to prove its validity or its reliability as a therapy approach. I also heard that he and his co-author subsequently divorced. Hence my advice to "proceed with caution."