Is CC0 not closer to being public domain? My understanding is that placing a work into public domain is actually non-trivial, so if that's really what you want to do you should use a license explicitly geared toward that:

https://creativecommons.org/publicdomain/zero/1.0/

I'm guessing that's not what you wanted, because when something is truly public domain then you lose any ability to control it whatsoever, but it is what you asked for.