I share your pain. One way to get around it is to use the Chrome 'multiple profiles' feature, it lets you switch to a different 'profile' with entirely different cookies, cache, etc., and will let you sign into a different Google account than in your first profile.
You can switch profiles and even have different profiles active in different Chrome windows, without restarting Chrome.
(I am not saying this makes it all better, trying to use more than one Google account is a _mess_ no matter what. But that it's one workaround I discovered recently, which has been lessening the pain somewhat)
The profile switcher is nice - would like Firefox to support fast switching out of the box. But here Chrome is going a little backwards too. Recent work has made that profile switcher a bit less convenient. Many complaints here:
https://code.google.com/p/chromium/issues/detail?id=403619
You can switch profiles and even have different profiles active in different Chrome windows, without restarting Chrome.
https://support.google.com/chrome/answer/2364824?hl=en
(I am not saying this makes it all better, trying to use more than one Google account is a _mess_ no matter what. But that it's one workaround I discovered recently, which has been lessening the pain somewhat)