Keep a disposable plastic spoon inside the Ovaltine container. That way, you don't have to dirty a new spoon every time you make chocolate milk. What's that, you say, you still need to dirty a spoon to stir? Not if you use a sippy cup! Just screw the lid on, put your finger over the spout, and shake!
Note: Putting your finger over the spout isn't technically necessary, but sometimes, shaking creates enough pressure to open the valve (especially if you are making warm chocolate milk), so it's a good precaution.