[Mordisquitos]

But in the case of drugs there would be a clear motivation fuelling the alleged myth: to perform illegal searches based on the fake prior of "illegal drugs" having been sniffed by the dogs. That does not work for electronics.

Carrying or distributing certain drugs is illegal, and thus a sniffer dog ostensibly detecting them can be grounds for reasonable suspicion and a search. Being suspected of carrying electronics, on the other hand, is not grounds for a search. That is, of course, unless these dogs are claimed to be trained to sniff out only electronics storing child pornography... ¯\_(ツ)_/¯