People have used prayers for healing since ancient times. I consider prayers to be a form of meditating.
From the San people to the Irish people, from shamans to catholic priests, people from all different cultures have used prayers to heal. Can prayers really heal though? I believe they can and do heal, I have seen it for myself.
I have heard that statement more than once, my answer to that, is the only thing that matters is that it gives comfort, relief and strength to the person or persons involved.
I cannot see what there is to gain by trying to debunk this. This a personal matter for the person or people involved.
I am not religious but even non-religious people can gain some benefit from listening to prayer. You don't have to be religious to appreciate the words and the meanings behind prayers. All you need is an open mind.