Chickens aren't really perching birds like sparrows and robins. They do roost but need something wide like a 2X4, especially in cold winters so they can cover their toes with feathers to protect from frostbite.
Sometimes young chicks will perch on something like a dowel rod but most often they sleep on the floor till they're brave enough to jump onto a roost.
x2 Either a 2x4 set with the flat side up so they can sit on it, or very large limbs. I use both, a 2x4 in the coop and I have two large branches (over 2" wide) in the run.
Raise the feed and water and cover them so they can't defecate in them.
Just adding perches won't prevent them from standing on feeders and water founts. Sitting on and defecating in their food and water is their favorite pastime.