The nontraditional approach in question turns out to be seeing patients as human beings that are suffering, rather than as manipulative ghouls.
Wile dedicates a great chunk of the book to describing what his approach is a counter-approach to. Distancing itself from the dismissive "separation-individuation" of psychoanalytic approach, from the nonverbal and paradoxical methods of Jackson-Haley method, and from the transactional nature of behavioural approach.
Wile's "nontraditional approach" ends up being a back-to-basics approach to therapy - communication, observation and saying the unsaid between the partners.
Wile ends the book with a couple dozen pages defining his approach: building conflict into the relationship and building fantasies into the relationship. The definition seems like a ¾-boiled idea, which it is, as this was when Wile was still forming his "Collaborative Couple Therapy" over decades to come. I will need to read his later work, but this was a great entry.