Maybe there should be a way to make a link that will remix as an anonymous user?
Then the user can see the output in the console, make changes, and remix the changes into their own account if they actually want to save it. This would be great for an embedded jsbin / gist / code pen style viewer.
As a user I would find it strange if each blog I visited created new projects in my account if I was logged in (which sounds like what may happen if a remix url was used in an iframe, but I have not tried).