I have wooden platform stands that the squirrels love to chew on. A few years ago I added lots of cayenne pepper to the solid stain which I painted onto all of the edges. Seems to have worked. I climbed into a stand a few years ago and a raccoon was sitting in it...not fun, but we both got out of each other's way without anyone getting hurt. I always shake the stand a lttle before I climb the ladder now.
Keep life simple...if you hear hoofbeats, think horses, not zebras.