This Buddhist technique (mainly from the rinzai school) is helpful in reaching a state of enlightenment.  Most often it has the form of a question or a Problem based on paradox.

In Coaching this technique of asking questions is also based on paradox.  It shows the lack of consequence and logic between a particular Behaviour and goal which should be reached through acting in that particular way.  The client, after hearing such a question should realize the impossibility of reaching his goal through such action.  This question does not require the Coachee to answer, which anyhow would by impossible due to a lack of link between behavior and the target.