Interventions that should work in theory often do not work in practice.
An explanation of how or why an intervention may work does not mean it does work, or that it is safe. And even if an intervention works in a way that it is likely to be helpful, it is not possible to predict how helpful or safe it will be.
For example, switching from petrol to diesel powered vehicles was thought to benefit the environment due to lower carbon emissions but evidence has since shown that diesel vehicles cause significant air pollution problems.
BEWARE if a claim about the effects of an intervention is based only on an explanation of how it works.
REMEMBER: Interventions that should work in theory often do not work in practice.