Jala neti  is the practice of gently flushing your sinuses with salt water (recommend adding one-quarter teaspoon of non-iodized salt for every 8 ounces of water). Once you get used to practicing neti it can easily be slotted into your daily routine and yes ,you can do it in the morning and at night .It's  helps to have a good relaxing deep sleep if you do it at night ...

Neti preferably only in morning.Can use a few drops of sesame oil(teel tail) in water for jal neti