The line running from alarm to reason is wide, and the line back is thin. A skill you have only read about will not be there when you need it, and one you have rehearsed will.

What the research says

In a randomised experiment, repeated practice on small self-control tasks improved later self-control performance, suggesting the capacity can be trained, though the study was small and short term. In another randomised trial, a structured motivational self-talk protocol offset the performance cost of prior mental effort in 37 competitive swimmers. Both are small studies well outside the world of arguments, so take them as support for rehearsal in general rather than for any one script.

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