This is simply not a correct understanding of Church teaching. The Church admits of no such “exceptions” for “health reasons.” Masturbation is an intrinsic moral evil (
CCC 2352) and one may never do evil that good may come of it (
CCC 1789).
The only things that would reduce culpability would be what the CCC says: “To form an equitable judgment about the subjects’ moral responsibility and to guide pastoral action, one must take into account the affective immaturity, force of acquired habit, conditions of anxiety or other psychological or social factors that lessen, if not even reduce to a minimum, moral culpability.”
Notice, it does not say that masturbation done for the purposes of “physical release” would have any effect on culpability.