the better way is probably to store this particular sensible password on a piece of paper , stored in a safe place.
I also like this old idea. I actually have a little notebook which I keep somewhere but I just make sure that nobody can access it. Anyway, there are only two of us in my house and I am sure the other one does not know anything about the computer so I am 99% safe...except maybe if there can be a fire that can happen in my neighborhood then it can be a challenge lol. Having a good copy of our passwords is a good idea.
You could get a small fire safe and store it in there in case a fire were to occur. You'd probably also want to store it in a water proof bag or something to prevent possible water damage.
A fire safe would be waterproof in itself, so you wouldn't need to have a water proof bag. Admittedly though I don't actually do this as it would take some effort and cost money, I just keep paper in my house. I recognise that someday there could be problems, but I actually keep paper in two different places, one of which is outside and more difficult to access, so I know that if one is ever destroyed I can still recover my passwords.
What's important is that your passwords aren't online as that could be prone to hacking, even a browser extension. If you can be bothered, holding your passwords offline and formatting them as previously described could be a very good idea if you keep backups. Ideally you could just hold them on a secondary low quality PC on which you don't go on the Internet, so that you're very unlikely to be compromised, and back them up when you add new ones.