I mean daily testing until we have two weeks of zero cases. Worldwide (or mandatory two weeks isolated quarantine at customs). This is what new Zealand did, so it is possible, but it is logically very hard for anyone not an isolated island.

Worldwide with quarantines from customs is virtually impossible. Customs can't stop human or cocaine trafficking from making it into the country, much less undocumented immigration. All you need is a half dozen sick people who are trying to hide from the authorities, and you're back to square one. Most countries are not islands.

Like I said, logistically impossible, but it would work.