Using Self-destructing cookies add-on I have Firefox set to remove all cookies on exit/ close: Custom settings for history unchecked: always use...remember my brow...remember search... Accept cookies from sites (with an exception list that works correctly) Accept third-party cookies: never Keep until: I close Firefox Settings: all checked to clear except site preferences. I had been noticing a very long list 50-100 cookies identified by CC Cleaner as being on my system that Firefox dis not display. So I began using the Self-destructing cookies add on. The app definitively shortened the list. However, cookies still remain after closing -- per CC cleaner. Some are api.websitename.com others appear to be flash cookies. Why are they not being removed? Thank you.