Popsugar food has a video up detailing how to make your own home-made Wendy's frosty only on three ingredients: condensed milk, chocolate milk, and Cool Whip. It all seemed so simple as she mixed the three ingredients, until the big kicker came in that you had to have an ice cream machine. Sure, if you have one, that's great, but for the rest of the regular folk with no extra disposable income to get one, that's just a no go.
Fret not, though, as a viable suggestion from the comments came in if you are like me who happen to not have an ice cream machine lying around the house.
"To those without an ice cream maker, Brothers Green Eats did a video on this and froze the chocolate milk in an ice cube tray. Then they blended the chocolate milk ice cubes, the condensed milk, and cool whip in just a regular blender."