[,,,]

The reason it works so well on the river is because of Banon's heal ability. You can walk away for days or weeks and your party will be fine. If you tried the Zozo trick you'd have to keep checking back to make sure everyone's alive. Unless there's no combination of enemies that could even hit you before you took them all out. You'd have to test that.

Or if you fought those things that cast vanish on themselves and one managed to do so, it would eventually kill you since all your guys would be attacking. Again, unless it's impossible for one to live that long.

And like you said, it's much slower than the river trick, so someone would need to be able to walk away from the tv probably for a week.

But it's an interesting idea, I've never heard it before.