In Hongdae, Daiso Hongdae 2 (182 Yanghwa-ro) and Hongik Univ. Store (25 Hongik-ro) are near Hongik Univ. Station and open until 10 pm, fine after an evening out. 편백 큐브 신발 탈취제 is a 2-pack of cypress cubes for ₩2,000 (2.6K+ orders) with a light wood scent, nice for your shoe cabinet at home too.