There isn't a widely recognized and accepted therapy technique where a therapist intentionally says insensitive and hurtful things to their clients. While therapists may sometimes gently challenge clients or explore difficult emotions, the goal is never to deliberately cause harm or distress. Therapy is intended to be a safe and supportive space for clients to process their emotions, gain insight into their issues, and work towards healing and growth.
The therapeutic approach you described could be harmful and unethical, as it goes against the fundamental principles of providing a supportive and empathetic environment for clients. Effective therapy relies on building trust between the client and the therapist, and intentionally causing pain could damage this trust and potentially exacerbate the client's issues.
There are various evidence-based therapeutic techniques that focus on uncovering and working through buried painful feelings from childhood. For example, psychoanalytic therapy and some forms of psychodynamic therapy explore how early life experiences may have shaped current emotional patterns. Cognitive-behavioral therapy (CBT) also helps clients identify and challenge negative thought patterns and beliefs that may have originated from childhood experiences.
If you are considering therapy or are currently in therapy and feel uncomfortable with the techniques being used, it's essential to discuss your concerns with your therapist. Open communication with your therapist is vital for a productive and beneficial therapeutic experience. If you ever encounter an unprofessional or harmful therapeutic approach, it's essential to seek help from a different, qualified therapist.