How likely are you to use them in an actual confrontation though? Probably not likely, you would have to be put in a situation where other forms of neutralizing the situation are not possible (this includes running the fuck away); and at that point, primary importance is having a very limited set of general techniques that can be applied in multiple situation with the weapon so that through practice and training it's more of an autonomic function of your body (you don't want the lag of having to 'think' about which technique to use); secondary importance is experience with these situations - i.e. one of the marital arts groups I worked with would have us go to, and shoot at, a firing range so that we were used to the sounds that a gun would make at close range so that we were used to it in the unenviable case of being in that situation.
Generally, disarm techniques are going to be extremely similar, but with any sharp object it's going to be - expect to get cut, deflect with non-vital parts of your body (such as the outsides of your arms, not the supple insides of your wrists), and neutralize the weapon as quickly and safely as possible. Some martial arts systems even have scarf techniques for doing disarms with soft objects from a distance (it's super cool seeing someone do a gun disarm with a cloth/scarf).