Great extension! Really handy to have different "views" into a website, each with a different account and cookies, etc.

I had trouble disassociating sites from Always opening in a particular container, but here's how you do it: You have to open the extension from the toolbar > Manage Containers > My Container XYZ > Manage site list.

The interface is odd because a similar but different set of options appear when you hold down the new tab button and choose Manage Containers, it doesn't have the Manage site list option there! The Manage site list isn't in the Extension settings either.

I had originally accidentally associated google.com with a container, so whenever I did a search, it asked me if I want to open the website in the container or no container.