You can’t get rid of the virus that causes a cold sore;it is caused by the herpes simplex 1 virus. However, you can keep the area clean by lightly washing the cold sore twice a day with just soap and water. You can also keep the cold sore covered with an over the counter first aid ointment. Keep your hands clean and do not pick or bust the blisters on the sore. That will spread the infection. You can spread it by touching it and passing it on to others.