All you can get this way is that you'll still have temporary cookies,
removed after closing the tab, you will still have the banner, but this
time the banner will popup each time you'll enter the website, because
there's no cookie that will tell the banner that it has already been
displayed.
I have it like this. But with that, I'm using a banner autoclicker. So
the company gets my data, although different each time I enter the
website, and I don't see any banners. Win/win?
If I do not want a website to set any cookies, the correct course of action is to tell my user-agent to not keep any cookies from it.