Do they still spray disinfectant in planes?

They do, but the methodology has changed.

Until about a decade ago, passengers on all aircraft arriving in Australia would be told to remain seated when the aircraft docked, crew would open the overhead bins and a pair of chaps in khaki would march down the aisles with a can in each hand squirting a fine spray of insecticide into the air.

This was intended to slay any insects that might pose a threat to Australia's biosecurity.

Among passengers coming to Australia for the first time, incredulity or snorting mirth were common reactions.

What happens now is the Department of Agriculture grants approval to airlines to perform their own disinfection treatment.

Disinfection spraying is carried out at the last overseas airport before departure for Australia.

Treatment takes place after catering has been loaded, with the airconditioning system switched off, the overhead bins open and before passengers have boarded.

If the required disinfection has not been carried out, the aircraft will be sprayed on arrival prior to passenger disembarkation.

This is a rare occurrence these days, but make no mistake, those khaki-clad chaps are still there on standby.