If you recall, Dewey is highly reactive to common household items like the vacuum cleaner (see an example here). After just two sessions of desensitization and counter-conditioning Dewey made tremendous strides to his reactivity to the vacuum. When we first uncovered it at 40 yards away he did bark at it, but after just a few repetitions he was offering a Conditioned Emotional Response (CER) by looking to his handler when the vacuum was turned on (see video below). Such great progress!
Jeff Dentler, CPDT-KA, FFCP, CTDI