After my shoulder break and dislocation last year the first doc who was set to do the surgery wanted me to wear a sling to stabilize the joint for a few days before surgery. As it turned out I couldn't be intubated for surgery, so that didn't work out.
I switched to another clinic and got two opinions. The senior ortho doc said I could wear the sling occasionally if it felt better. The younger resident said to skip the sling. I wore it occasionally on long walks when the joint would ache and feel crunchy after a mile or so. Otherwise I didn't wear it at home.