Dear Russell, apologies for my delayed reply.
I've investigated this further, Cookie 5 does not appear to clear all cookies even on a browser restart.
I have Cookie 5 set to clear all data on Safari quit, which it appears to do when watching Cookie delete all of the data when I quit Safari.
However, if I login to let's say eBay, then quit Safari and reopen then go back to eBay, I am still logged in so Cookie 5 has not cleared all data as requested?
As stated before in my first post when I quit Safari which should clear all data (and via the Cookie panel it appears it does), when I start Safari and goto the privacy tab there are still cookies there that Cookie 5 do not show.
Could you investigate this behaviour please and report back?