Daiso Myeongdong Main Store (43 Myeongdong-gil) and Olive Young Myeongdong Town

(53 Myeongdong-gil) are on the same street, a few minutes' walk apart. At Olive Young, look for AROMATICA Rosemary Dry Shampoo Powder (10g, 2,930 reviews), a powder so fewer liquid worries. Pack the 150ml spray in checked luggage and check your airline's rules.