This will help reduce swelling and dry up or draw out any infection that might be present in the gum boil. Fill half a tumbler or glass with lukewarm water and add half a teaspoon of standard table salt. Mix until the salt is dissolved. It doesn't matter if some remains in the bottom of the glass. Use the saltwater as you would your usual mouthwash, but be careful to keep a special emphasis on the infected site when you're rinsing. Do not swallow the saltwater.  Continue washing with the salt washes once or twice a day for a week to help heal the boil. This will reduce chances of it coming back. At the same time, be sure to maintain a good dental hygiene routine. This method is recommended by oral health professionals and is clinically proven to be effective, but is not a replacement for a visit to your dentist. Applying essential oils topically to a gum boil can help reduce the levels of bacteria present and improve the overall tissue health. Combined, these factors can lead to the dissipation of a gum boil without needing to seek professional help. Simply add a few drops of the essential oil to a glass of water and rinse your mouth thoroughly.  Some good essential oils to choose are spearmint or peppermint oils. Be sure not to swallow the essential oil mixture. Remember that this is a recommended home remedy and has not been proven effective with scientific evidence. Consuming raw onions can be a very effective home remedy for treating gum boils. Onions contain relatively high levels of sulfur, which can help heat up and dry up existing boils in your mouth.  This is a home remedy and may be less effective than other solutions that have been verified by medical professionals. If you don’t like the taste of raw onions, try eating them on other things — like in salads or on sandwiches where the flavor is masked. Don’t cook the onions as this can reduce the amount of sulfur present in the vegetable.

How would you rephrase that briefly using Vietnamese?
Súc miệng nước muối. Sử dụng tinh dầu. Ăn hành sống.