Systematic desensitization is a method used to help people overcome fear or anxiety by gradually exposing them to what scares them in a controlled and safe way, until they become less afraid. Full definition
«The efficacy of systematic desensitization for treating the separation - related problem behaviour of domestic dogs.» (malenademartini.com)
Counterconditioning works best if done with systematic desensitization. (pethelpful.com)
An alternative, is to try systematic desensitization under your dog's threshold levels so to help him better cope with the frustration since the trigger will be made less salient. (pethelpful.com)