I merely relate that which my doctor told me when he first supplied me with some.
There is i was led to believe some difference between salt tablets (to replace salt lost through sweating) and these electrolytic salts whose function is to help retain fluid rather than allow it all to pass through.
I seem to recall some packaging a while back appearing to confirm this description.
of course I could be entirely wrong (it wouldn't be the first time) but I can only tell you from experience that copious water drinking doesn't work as well as smaller quantities containing these salts.
You can obtain neutral flavour as well as lemon though the supermarkets tend to offer blackcurrant.






