Anyone who needs laundry needs while traveling in Korea, there is coin operated laundry stores that are open 24 hrs. The following is the link to to the store directory

http://www.coinwash24.co.kr/gnuboard...bo_table=chain

(Unfortunately the website is in Korean so you may need Korean assistance.)

The one store I used charges 4000 KRW for wash load and 3500 KRW for a dryer cycle.