I know I can delete the Cookies.plist file to get rid of ALL of them for good.
does that actually work, if something resurrects them?
Yes, because that "something" is the Cookies.plist file.
I'm pretty sure it works like this:
To prevent permanent HD access, Safari loads existing cookies once at launch from HD, then keeps a copy of its cookies in memory and only occasionally writes the changes back to the file on HD. Apparently the bug causes the cookies to be only deleted in memory, but those changes are not written to the file, so every time Safari syncs, they come back. Closing Safari (to kill the memory cookies) and then deleting the Cookies.plist will get rid of cookies for good.
BTW, this allows a way to make session cookies. Go to your user Library > Cookies, delete the existing Cookies.plist file, create an empty text file in TextEdit, safe it as Cookies.plist in that folder, then lock it (Cmd-I, check "Locked") or/and lock the Cookies folder. This prevents Safari from writing any cookies to disk and it will only work with the cookies in memory. When you close Safari, they are all gone.
Do you have the
"Warn when visiting fraudulent sites" box checked in your Safari preferences?
Because that is a Google service. That might explain Google always coming back.
No, I haven't and it doesn't. Google analytics cookies are always served from the domain that uses the analytics service, i.e. you'd have to visit that site again. You can tell the cookies only by their name. They all start with "__utm":
Check your cookies, you'll be surprised how many of those you have!
There are others that behave the same way: __qca and __qcb are [Quantcast|http://www.quantcast.com> tracking cookies, _csuid are [AddThis|http://www.addthis.com/features] tracking cookies. Would be cool if there was a filter by cookie name that blocks those in the first place. Seems Safari Cookies only deletes Google Analytics cookies when quitting - which I never do, my Safari stays sometimes on for days (until it crashes which it likes to do way too much) as I only put the computer to sleep. But I'll try it out. Thanks for the suggestion!
Still disappointed though that Apple can't get this straight after people've been complaining about this bug for over a year. Feels weird that I need a 3rd-party app for something so basic as deleting cookies.