For each account,
> Create a long, unique, random password.
> Save the site URL, the required userid, the password, and any other relevant things in a text file.
> Save all these text files in fossil.
> Password protect and save the fossil file with 7z.
When it's time to use a password, run a script to unzip the 7z file, fire up fossil, and expose the full set of password files, then access whatever I need.
When done, delete everything, leaving just the original 7z file.
Is it a little tedious and clunky? Yep. Does it work? Yep. Is it totally under my control? Yep.
Details
> Generate a 24-char password: gpg --gen-random --armor 1 18
> Fossil: https://www.fossil-scm.org/home/doc/trunk/www/index.wiki