The Acid Bottle was a weapon in the beta version of Manhunt 2. The audio files for the executions still exist in the PC version. It's possible that it was removed, due to the developers not wanting three different bottles in the game. The acid bottle may have been in Origins, as this is a likely setting for the item. The Acid Bottle was likely a green class weaponThe jump execution audio for it sounds similar to the Nightstick, Dildo, and Flashlight jump executions.