Have not tried this myself and don't actually have anything against squirrels. But I was talking to a relative who saw this done, said it works flawlessly. Take a five gallon bucket and put about 12" of water in it. Stick a large diameter PVC pipe into the bucket and lean the end up against a tree trunk. Smear peanut butter onto the inside of the pipe so that it is up out of the water and able to be smelled. Use your imagination as to how it all unfolds.
This relative has seen property where this has been employed and it is absolutely vacant of squirrels.