Article in English: Home remedies with natural ingredients are always an uncertain science, and the U.S. National Institute of Health doesn't report any to be consistently effective in all cases. Anecdotally, however there are a few things which may have a calming effect on cold sores. You can apply a few drops of pure vanilla extract to the cold sore using a sterile cotton ball three to four times per day.  The vanilla is alcohol based, and will function in a similar basic way to the rubbing alcohol. Vanilla extract also reduces inflammation, making the cold sore less painful. Only use 100 percent pure vanilla extract. Do not use artificial vanilla, since it does not contain the same anti-infection properties. Tea tree oil is used as a treatment for a variety of skin complaints, and can be used to ease the symptoms of a cold sore. It dries out skin very effectively, which can help your cold sore's healing process. It also has antiviral, antifungal, antiseptic and antibiotic properties. Dab it directly onto your cold sore with a cotton ball twice a day.  If you have sensitive skin, you may want to dilute the oil with equal parts water before applying it. Tea tree oil is toxic when ingested, so take care when applying near the mouth. Be aware that some research has suggested that using a 6% tea tree oil gel five times a day had little impact on cold sores. You can apply sea salt directly to cold sores on the outside of the mouth or you can gurgle salt water to treat cold sores inside the mouth. With clean hands, press the salt gently into the cold sore and allow it to sit there for around ten minutes before you wash it off. You can do this treatment two or three times a day.  Gargling with a salt water solution can ease a cold sore. Add half a teaspoon of salt to a mug of water. Swish the solution in your mouth for several minutes. The minerals in sea salt are thought to heal broken, inflamed skin, thereby reducing the severity of cold sores. Witch hazel has long been used for medicinal purposes, and it can be used to treat the...

Summary in Vietnamese:
Dùng tinh dầu va-ni. Dùng tinh dầu chàm. Dùng muối biển. Dùng tinh dầu cây phỉ.