Gritting your teeth works right up until you are tired, hungry or already stretched. Watching the anger from a small distance is the steadier option, because it does not need holding up.

What the research says

In an experiment with 200 police recruits, a demanding task that drained self control raised their stated intention to use force in a video scenario, which fits the idea that restraint is spendable in the moment. Separately, across two samples, people higher in trait mindfulness reported less anger, hostility and aggression, with less rumination partly explaining the link, though that design cannot show which came first. One experiment and one cross sectional study is thin ground, so hold the conclusion loosely.

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