Cook macaroni according to package instructions. Drain and place in a large bowl. Add vinegar, onions, carrots, pickle juice and pickle relish. Toss to combine then allow to cool completely.
In a small bowl whisk together milk, mayo, sugar and black pepper. Toss dressing in with macaroni and mix to combine. Cover and place in fridge for an hour to let cool.
When done, sprinkle with chopped green onions (optional). Serve with your favorite main courses!
Notes
Store leftovers in an airtight container for up to two days.