In a heat-safe measuring glass, combine the 6oz of Watermelon Jell-O and 2 packets of unflavored gelatin. Mix to evenly incorporate.
Add the 2/3 cup of boiling water to the gelatin mixture. Mix thoroughly until everything is completely dissolved.
Carefully pour the liquid into silicone candy molds.
Toss into the fridge for a minimum of 2 hours to let the gelatin set firmly.
In a separate bowl, prepare the sour coating by mixing 1 cup of sugar, 1 tsp of corn starch, and 2 tsp of citric acid.
Pop out the chilled gummies and toss them into the sour sugar mixture until evenly coated. Serve immediately.
