I used pickle juice and I also bring mustard packs to the courts.
The Mustard packs I would use if I felt a cramp coming on.
I have not had to use pickel juice or mustard in a long time (thankfully).
Another thing I do is drink chicken broth. Not all the time. Maybe once a week. But it basically tastes like chicken soup and helps keep me hydrated.
Please help TT Member BruceD get a wheelchair so he can play tennis again - http://tt.tennis-warehouse.com/showthread.php?t=496820