The Winchester's have their ways to take down things that go bump in the night, Hell go bump in the day as well. Not all weapons that I will be talking about have been used by the Winchester's themselves. Some of these spells have been used during the show and changed dynamics of that particular episode.
Today focus is Binding Ghost
The Binding Ghosts is a spell that allows a person to bind a ghost to their will to perform whatever task they demand, including murder.