It appears to work, but after using it to "clear everything" and then open a new tab and going to a site where I was previously logged-in before "clearing everything", I find I am *still* logged in. So, at least cached passwords are not being cleared -- which is probably the most important thing one can do with a tool like this.

Also, it would be nice if the "success" notification disappeared all by itself after 15 or 20 seconds.