Decoys, I can generally tell when they have my DNA. I lead them into a shit tier spot where people can't see, kill them, problem solved.
I don't use the flare gun anymore. I find it useless. If you are in a private area to pull out a T weapon and burn the body, why not just hide it? or place a decoy. The DECOY is useful. @Darth Gorgamel what it does, if you don't know, is it makes DNA useless if placed in a T room. Basically if someone gets DNA on you, it will lead them to the decoy first. Most useless T weapon? Flare gun. Most useful? Decoy or death station. Could be useless but still used by me as a troll item. The poltergeist, newton launcher, and malfunction pistol.
I dont use the Tear Gas nor the Flare Gun alot. Love to troll with Newton especially on maps like Dolls and Rooftops Best One for me is SVU because im a good sniper!
Harpoons. For several reasons: 1: they are bugged where you can throw through thin walls. 2: they are hard to aim and are a dead giveaway. 3: only give you one kill while others give the potential for several kills