Is there a way to make a safe pedialyte-type of electrolyte at home for my child?

Water, salt, sugar: It is easy to make an oral rehydrating solution at home to be used when your child is throwing up. Take 5 cups of clean water, add 6 teaspoons of sugar and 1/2 teaspoon of salt. Stir until the sugar dissolves. Initially, give very small, frequent amounts of the liquid to your child, allowing their stomach to get used to having fluid back in it. Wash hands well to avoid spreading the illness.

Homemade 'Lytes: The who has lots of resources online about types of dehydration solutions, but here is a simple recipe adapted from rehydrate.Org: -six (6) level teaspoons of sugar -half (1/2) level teaspoon of salt -one litre (~ 4.5 cups) of clean drinking or boiled and cooled water.