The aim is not to stop feeling angry. It is to stretch the time between the feeling arriving and you doing anything about it, from no seconds to a few.

What the research says

In a platform trial of metacognitive therapy for treatment resistant depression, an approach that works on a person's relationship to their own thinking rather than on its content, large improvements were maintained at six and twelve months. The trial was uncontrolled, so it cannot separate the treatment from time passing. It fits the idea that changing how you stand towards an inner state, rather than removing it, can hold.

Strength of evidence: one line of research. A single study, or a theoretical account.