Originally Posted by
UA1K_no_more
Small datapoint: On my last ten flights arriving in Australia (seven flights originating in the US, two NZ flights originating in New Zealand, and one NZ flight from the Cook Islands), I've gone through the spraying process once (arriving from SFO on UA).
Not a common occurrence. Since there are a lot of NZ flights to Australia every day, I assume that they make sure to fumigate the aircraft according to AQIS specifications to avoid the on-arrival spraying.
I asked a few other friends that have flown to Australia and none of them remember the plane being sprayed before they deboarded. I thus thought that it may have occurred on our flight because the flight was diverted to a different airport.
I read that the planes are sprayed but it doesn't appear to be routine to spray the plane while on the plane.