In many cases, it’s simply not possible. Shame is a very debilitating emotion. It makes people “busy inside” and reduces the resources and presence they have available to meet needs and survive.
Evolution has prepared the brain with a very powerful program called “homeostasis preservation”. It’s the fuel behind processes such as denial, emotional reasoning and dissociation. It’s job is to keep each of us from becoming destabilized and thus weakening our coping strategies.
When you try to tell someone something shaming, you are triggering that program to perform mental tricks to push this destabilizing information OUT of awareness.
They will deny, deflect, dissociate and otherwise dismiss you as having an agenda, and being totally un-credible.