It is mistaken to be poison, until Kuro smells it, recognizing it from when Fujimoto offered it to him. 
There also exists an Izumo Special Catnip Wine created by Izumo Kamiki. Made with children's beer, non-alcoholic champagne and fish flakes. While it was supposed to be left for three to six months, she left it to mature for only three days. It caused Kuro to faint after barely tasting it.