Not a single Catholic, qua Catholic, venerates the dead. All of the saints are alive in Christ, they have survived as St. Augustine puts it, the second death. Catholics are forbidden from praying to deceased relatives and friends since they may not be in heaven. But canonized saints are in the glory of the beautific vision, wrapt in the unimaginable Love of God. Any Grace we receive through their intercession comes from Jesus Christ. The Communion of Saints is a lovely thing. We get to participate in God’s gift giving. Much like human parents get to participate in bringing a new person into being and into eternity from nothing.
The miracles associated with holy relics, whether it be things associated with saints such as clothing or articles or bits of their bodies is undeniable, often unexpected. If one’s reality involves denying this reality, what type of reality is it? There is also the problem of incorruptibles. Why does God preserve some of his saints bodies incorrupt? Why is St. Jacinta incorrupt? Why is St. Rita de Cassius incorrupt? Why was the heart of St. Joan of Arc found incorrupt in the ashes? Or the tongue of St. Edward the Confessor only? What is God trying to tell us? One can deny such things, but they do exist, and such denial is again someone’s safe little reality that is not real.
It really doesn’t matter what fluff stories any religion attaches to these....the fact these are unburied dead skeleton remains and decayed dismembered body parts cannot be denied..... How people choose to prevent burial, regardless of what religion, and what rituals they practice ‘believing’ that these body parts have some sort of mystical power or holy part in their worship is, as mentioned prior, well known among Haitians, Pagan tribes in Africa, soothsayers and the like.
This is not something Jesus practiced nor did he encourage us to do so.