blocking cookies in Safari
I have an iMac 14,3 running Sierra 10,12.6. Recently, out of curiosity, I erased all the cookies present in Safari. Then I turned on the 'do not allow cookies". I closed safari then reopened it and went to the cookies window. Everything was gone but even as I watched around a dozen or so reSaappeared. I repeated these steps numerous times and in various orders with the same result. The same cookies reappeared almost immediately. I inquired about one titled Outbrain. From what i read I do not want it on my machine. But, I don't know how to avoid Outbrain or any of the others that circumvent the "no cookies at all" rule.
Please help?