[Guest9812398]

What about going back to the notebook idea? You give them a notebook that's called 'Passwords' and it sits on the desk beside their computer. They only write passwords in that notebook, and you can explain to them to write at least 20 random numbers and letters for new passwords.

When you visit, you can write those passwords down in your password manager. This way if the book goes missing or there is a disaster, you have a backup.

[FooBarWidget]

They lose the entire notebook. The thing is, they only need login credentials a couple of times a year or so. Things like social media and email are apps that are logged in all the time so they only need to reauthenticate when something is wrong or when a special event happens (like buying a new phone). So that only leaves a thousand different boring things that they only rarely access, like the government ID, the utility company account, the insurance company account, etc. So every time they have no idea where that particular notebook is among their tens of other notebooks, pieces of papers etc.