You never new with Joh - he also backed a "hydrogen car" with doubtful claims [1 - pdf], the government ended with a number of criminal charges for ministers and Joh himself.

[1] https://www.skeptics.com.au/wp-content/uploads/magazine/The%...

But it would change the times people have their curtains closed.

(Not that I think it's a particularly good argument. And no, I'm not in the pocket of Big Curtain)