Sorry but this all sounds pretty terrible to me (sherbet is that fizzy powdered kind of candy sold in tiny packets over here, is it the same thing you're talking about? I would never have thought to put it in water!)
That's why I was like 'why would anyone want to drink that?!' It makes think of drinking watery bicarb soda that I use for cleaning! blech! I think there was a time athletes would consume bicarb to reduce lactic acid build up but those super dedicated people will do weird things for an extra edge!
The only punch that I have ever really liked is "Hawiian Punch". I do not usually drink the punch that is served at showers and such...unless it's spiked!