There are many techniques for disarming and all are risky at best. Many of these have a person redirecting the weapon to either side of them. There is a problem with this concept, especially if the weapon in question is a firearm.
What if you are in a room full of people? Even if you avoid getting shot yourself an innocent bystander may be shot. There are other options other than redirecting to the left or right. Perhaps some other methods should be considered as well as professional instruction by a certified instructor. It is a helluva thing to train for, especially if you train yourself improperly.
Practice leads to patterns. Imperfect practice leads to imperfect patterns. It is best to get it right in a safe manner so as to avoid potential death or serious injury to yourself or others around you. Perfect practice will get the bugs out of the technique.
Keep it simple, if the technique require multiple movements and complicated maneuvers it is likely to fail. The more intricate anything is the easier it is the circumvent/ counter.
History is a freak show and a dark comedy. Mankind is a spectacle all to itself. Play your role, let the jesters play theirs. In the end...who has the last laugh?