The sunnah method involves rinsing the mouth three times. Jurists discuss whether using one handful of water for three separate rinses completes the sunnah.
One opinion requires fresh water each time for the complete sunnah method; a transmitted view attributed to Sadr al-Shahid considers three distinct rinses sufficient even from one handful. The point of disagreement is the status of renewing water, not the number of mouth-rinsing acts.