Bless your kind heart Chiron, who would not want to encourage wildlife? People are weird sometimes. I like your nut ball treat idea, and although the squirrels may not know its doing them good, you will know, and the one thing we could always use more of, is kindness :)
There is a good reason to go with natural remedies for our animal friends, I use their manure as fertiliser for my garden, so to use non-chemical means to help them with their health, means no chemicals get passed on in my garden soil.