Correct method of gargling the mouth for Shawafi

According to the Shaafi Mazhab, one should gargle the mouth and rinse the nose together with three handfuls of water. The method of doing so is that one will take one handful of water, gargle one's mouth, and with the remaining water in the palm, rinse the nose. One will repeat this procedure another two times.

And Allah Ta'ala (الله تعالى) knows best.