Re DuMor 5 grain scratch, here is a photo of what it looks like. It contains corn, wheat, sunflower seeds, barley, and milo. Many brands have only 3 grains. I can toss this to the flock and not have a dusty hand.
And yes, scratch and other treats should not make up more than 10% of their...
I like this one by Dumor….it has 5 different grains. It isn’t dusty. Some of the cheaper types have way too much milo, which my chickens don’t like so much.