CCUK
Free Flying
These are the nest liners I was on about. They are reasonably cheap. So far I have not had any broken eggs whilst using them.I have had the same problem with my Archangels. They keep on throwing all the nesting materials out so the nest has no padding so I have bought some nest liners that are quite soft that they can't remove. Also make sure they have a mixed grit for pigeons. It will have all the minerals in they need including calcium.