I may be wrong, but if you rinsed off the carcass I would think that it might be fine. It’s really the bones that matter in a broth.
I would not wash anything off. Smash the bones down in a skillet and cover with water. Not too much. Cover and simmer on low for about an hour. Let cool, strain and refrigerate. After its cold you can lift off and discard as much fat as you want.