Yes, his point was right on. Now as to how to obtain the necessary salts besides sodium chloride, there are electrolyte replacement powders and tablets that are helpful when losing and replenishing massive amounts of water over a short period. For many people that are not sweating or transpiring huge amounts of water and replenishing it by drinking similarly large volumes in a short time, the water itself often contains some electrolytes, and mineral salts unless it is distilled or deionized, and a normal diet replenishes many more.

One inexpensive way to get sodium chloride, potassium chloride, and magnesium carbonate in a drink mix, is to use Morton Lite Salt. I think this can be effective to boost the electrolytes in an otherwise watered-down Gatorade or Tang solution when the sugar-to-electrolyte ratio of those is too high. In other words, add some Morton Lite Salt to your water so you don't have to add so much Gatorade that you gag on the sugar.