Concept it good, but practically it's a different thing. Fails on few scenarios and doesn't delete cookies as often as intended.

Let's say, you want to delete all cookies automatically on startup, except the ones you mention as "Never". But on startup, those unnecessary cookies are not deleted! Why? Because, selecting "On Startup" or "Leave" will not delete cookies automatically for all intended sites. You have to still visit each website and apply "on Startup" or "Leave" for each individual website and then only it gets deleted on startup. Pretty pointless.

Try to work around this, so that, cookies get deleted automatically (except the ones you mention as "Never") without having to visit each and every website and apply individual options.