I go through my list of Web sited and uncheck all I do not want to be favorites.
I'm set up to remove all non favorites upon closing safari.
within a day or so all the old ones reappear, making the work I did worthless.
Cookie doesn't block cookies - it just makes it easy to remove them.
you could set up a timer if you don't close Safari very often - although I recommend clearing non-favs etc.. on a browser quit