Starting with a medium to large watermelon, slice it in half, and scoop all the watermelon out using a spoon/ice cream scoop. (Make sure to get all red leaving only the rind.) Set your watermelon rind to the side.
In a large pan, reduce your tincture down to a FECO. Add your flavor extract along with 4 cups of hot water. Stir.
In a large bowl, mix cherry, strawberry, and unflavored gelatin. Whisk together and pour it directly into your large tincture pan. Add 4 cups of cold water and stir until fully mixed together.
Pour jello mixture into your hollowed watermelon and refrigerate overnight.
Once set, trim excess rind and cut into slices! Enjoy!