During WW2, the Australians considered using Aboriginal weapons in jungle fighting in the Pacific. So non-returning sharpened boomerangs were considered to take out the necks and legs of Japanese soldiers. Next was a form of spear thrower (this time spring fired), and another weird weapon based on a net-casting spider. This was the special operations D-Ravidus which was a metal folding trip-wired, spring launched poison fanged metal device. The poison was deadly so collapsing the device into a conical shape could prove deadly to the handler. And then it had to be placed and the trip wire concealed and remembered where these devices were. In the lab they worked fine, but outside tests caused many injuries and the project was dropped as impractical. The Owen SMG seemed to be a good enough weapon as well as simple military knives!!!