The therapist ought to use questions which do not contaminate the clients model. There is no such thing as a resistant client, but there is such a thing as a therapist who doesn't know what to do with the information they are being given. Normal conversation is okay socially, but not much use for using language as a healing art. Clients have within themselves things they need to heal but can't access them. The nature of Clean Language is homeopathic, it excites the curative powers within.
Symptoms are unsuccessful attempts by the mind and body to heal itself.
So our job is to create a suitable context in which we can encourage those symptoms to be successful. Many approaches try to get rid of the symptoms, Clean Language is about the identification, gathering and blessing of those symptoms. Clean Language is psychoactive - it has the ability to recreate and construe contexts so that they become self healing. Thus the healing experience occurs in real time, right infront of you, in the pauses between your questions. There are response inviting gaps which are left after a question in which the psychoactivity takes place.