I have one hen who sits on everyones eggs, smashes them and she is always sticky and loosing all her feathers on her underside. Besides, killing her, is there any other way to make her mind her p's and q's?
Another option for broody hens is to isolate them somewhere dark - i put mine in a single cage with a blanket on it or in the shed away from the other chooks for a day or two. It usually shakes them out of being broody (and my chooks are really broody!!) At least give it a try before doing anything drastic