Originally Posted by terrymorse

Mechanics are not engineers, and they often do stupid things. Tell an engineer that you’re going to fire high pressure water near bearings, the engineer will advise against it in no uncertain terms.

Pro team bicycle mechanics are equally untrained in engineering and tribology, and they are just as susceptible to picking up stupid tricks, passed down from older mechanics who swear they’ve been “doing it for years with no problems”. I wouldn’t trust any mechanic with a high pressure wand, even the “pro team” ones who claim they are “smart” about how they wield it.

Spraying high pressure water anywhere near bearings is risky. Such practice isn’t allowed in any industry that I can think of. Except bicycles, of course, where myth and lore survive.