User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-95.115.178.15-20150801070415/@comment-24834479-20150805211941

While this has been discussed, we have not dwelled into what happens to demons after death. For now it is believed that they are destroyed, but if we want to do something with this in the future, we could make it so that there is an after life for demonized souls.