There are some good suggestions here. But one thing I’m not seeing is any mention of the fact that asking someone else to stop doing something that you know to

There are some good suggestions here. But one thing I’m not seeing is any mention of the fact that asking someone else to stop doing something that you know to be stupid but they think works wonders for them, well that’s a path that is fraught with much pain, wailing, gnashing of teeth, and frequently little success. So, before doing anything else, I would encourage you to take a long hard look at your side of the equation, since that’s all you can really control. How much pain is this really causing you? How much potential damage are they likely to do when their Hindenburg does finally run aground? How far are you willing to go to try to help them do their job better? At some point, you’ve got to decide to fish or cut bait. Decide to either go somewhere else, or just live with it — while protecting yourself as much as you can. Figure out where that point is first. Periodically keep coming back to this question and make sure that point is still in the same place, or how it has moved if it has done so.