sterile yarrow
It will be a one time use and will look exactly like gtags firework launcher. This could function as a flare gun but it fires flares like a shotgun and has as much range as it takes to go across the entirety of frozen lake. It wil go exactly straight until it reaches the end of its distance then it will shoot and explode like a firework. you could make it so that you can buy flare gun ammo to refill the flare gun but not the firework. this way it will make them even
subtle garnet