Blowing your nose hard and fast can get rid of germs and mucus from your nostrils, but the high pressure can also force it back into your nose and sinuses.  Instead, blow your nose gently to get more mucus out of your nose. Using a soft tissue, close one nostril by pressing your finger against one side of your nose, and blow gently out the open nostril. Although you may want to lay down to rest while you are sick, laying down can make it harder for your sinuses to drain. Sitting up rather than laying down will help to drain your nose. Sitting up will pull the fluid out of your nose and make it easier to clear. Try using pillows to prop your head up at night and also when you are resting. Pouring lukewarm water inside your nose can help clear the mucus buildup. Try using a neti pot, which is a container used to pour salt water through a long thin spout into the nose.  Fill the neti pot with a solution of lukewarm water and salt. This solution is meant to mimic natural body tissues and fluids. Mix about 16 ounces (1 pint) of lukewarm water with 1 teaspoon of salt to create the solution for your neti pot.  To use a neti pot, tilt your head sideways over the sink and place the spout of the neti pot in the upper nostril. Breath through your mouth and gently pour the solution into your upper nostril so that the liquid drains through the lower nostril. Repeat on the other side. Rinse the device after each use with sterile, boiled or filtered water.

How would you rephrase that briefly using Vietnamese?
Hỉ mũi nhẹ nhàng. Ngồi dậy. Rửa mũi bằng bình hình củ tỏi.