I have shepherd hooks in my yard with all my bird feeders but have a problem with the squirrels climbing up the poles. I have tried oiling the poles using Pam, grease etc. and nothing worked. I finally decided to try a Slinky! This has worked great. I bought the Junior size which is 1.5″ diameter and it works great. Had to twist the Slinky around the pole and then I fastened it at the top with a hose clamp.
It works great!