Egg shells keeps peach leaf curl in check

[Dutchie in France]

first year when we planted nectarine trees they got tis peach curl very bad.
I sprayed the copper stuff and we carefully picked the affected leaves and burned them.
yet it came back and our little trees merely died.
a friend had the same type of trees and told us to put some egg shells in an sock and tie it to a branch.
I googled it, could not find if and how it would work, but tried it.
it is not gone but the trees are doing great and growing good, it is keeping it in check, really weird and what i found online is that it is an old French folk thing, but nothing really more.
Anybody an idea what the working are behind it? It is working better then spraying the tree

 

[DirtMechanic]

I have tied irish spring soap to plants and made deer disappear. For a while anyway.

 

[YumYum]

I'd be interested to know how egg shells can keep a fungus off your tree.

Irish spring does have a distinct odor to it. I don't know what is in it but no other soap smells like it.

 

[Dutchie in France]

I'd be interested to know how egg shells can keep a fungus off your tree.

Irish spring does have a distinct odor to it. I don't know what is in it but no other soap smells like it.

exactly, the older folks around here swear by it, the friend who told us had her nectarine tree growing very nice, while one of the mentioned nectarine trees with the fungus was a gift from her and it was from the same nursery. It is very weird