The candle you need is:
PHOSGENE
Enter the muddy trenches of World War One. Phosgene was deployed in trench warfare, with absolutely devastating results. We have followed the available historical documentation like a recipe, to create an accurate representation of a scent that ended many lives. Grass with a slight hint of black mould, musty wet hay and a slight sharp note of unripened corn. A grizzly historical masterpiece, which has been authenticated by a respected World War One historian.