I was recently ata very famous stone called the Cloch An Phoill and have since done some reading up on it. It is one of the few holed stones in the east of Ireland, but it's a bit of a cheat. It is not a holed standing stone but more likely a tomb door stone with a hole in it. These are quite common to the north and west.
Anyway, to get on to my point, this stone has the following bit of folklore attached.
Any child (it's a smallish hole) passed through the hole will be cured of all ills.
Sound familiar? What is the root to this type of story so commonly attached to a holed stone?