1) Cut the rhubarb, into small cube.
2) Do not peel.
3) In a saucepan, place rhubarb with water and cook until tender.
4) Stir in the sweetener.
5) Pass the mixture through a fine strainer or cheesecloth.
6) Mix the lemon juice and salt.
7) Refrigerate the mixture until chilled.
8) Crush the ice cubes and half fill the 12 pitcher glasses with it.
9) Add the ginger ale to the mixture and immediately pour over the crushed ice till full.
10) Serve the Rhubarb Ginger Punch immediately, garnish with juliennes of ginger if desired.