One could characterise Zen Therapy as Existential Tactical Therapy. Existential because it is much concerned with meaning and purpose in life, with spiritual dimensions in collision with reality factors, and Tactical because it employs challenge, disruption and reframing in a fairly systematic way. Thus, for instance, a client recently came to therapy with a problem and told the therapist that she has "a demon in her" that disrupts all her best intentions. The therapist told her that it is her demon that will have the key to the problem. This kind of reframing disrupts the client's habitual way of seeing things and provokes the client into thinking of new tactics.

There is an established approach to therapy called Strategic Therapy that owes a lot to the ideas of Milton Erickson. It also employs disruption. It has two main dimensions of disruption (a) disruption of perceptions and (b) disruption of tried solutions. It also has several styles for doing this (i) paradoxical injunctions (ii) prescribing the symptom (iii) forming an apparently subversive alliance with the client (iv) reframing weaknesses as strengths (v) challenging the client to defeat the therapist.

In ZT perceptions and their associated attempted solutions are the symptoms of the koan. There are several types of perceptions to disrupt: (a1) perceptions of the other person involved in the problem (a2) auto-perception (a3) perception of the therapist (a4) perception of the future and life goal.

There are then several types of “solution” to disrupt 
(b1a) giving power away to others, (b1b) attempting to change, bully or coerce the other 
(b2a) holding the moral high-ground, (b2b) self-blame, taking the guilt, withdrawal, passive aggression, 
(b3a) giving responsibility to the therapist, (b3b) assuming that therapy will prescribe such-and-such,
(b4a) clinging to ideals eg. Client: “I only want to do what is best for my children.” Therapist: “And I expect there are times when you can't wait to get a break from the little so-and-sos sometimes.”
(b4b) clinging to selfishness eg Client: “I just need to look after myself.” Therapist: “And a hundred other people, too, no doubt."

In other words, there are "solution” styles in relation to perceptions on each of the main dimensions and in each case there is a false positive style and a false negative style.

ZT also attempts to ground the process by the “Is that true?” or “what is true?” intervention when the client is getting caught in a “what does this say about that” type of chain thinking. e.g.. Client: I am thinking of going to see a solicitor without telling my husband. What does that say about me? Does it mean that i am secretly being unfaithful to him? That i don't really love him?" Therapist: "Well, what is true? Do you love him?"

In fact, ZT has common ground with many styles of Western therapy. It uses empathy, analysis, therapeutic alliance, homework tasks, systemic interventions and so on. where these are characteristic of different therapies in the west, the Buddha was willing to use whatever worked in order to break through to a more real encounter with the client and between the client and the Buddhas, each in their own way. The notion of ZT as ETT, however, is one useful way of seeing its profound yet provocative style.