Anyone tried Melatonin to calm an excitable dog?

We have a Schitzu mixture dog who will not let us cut the fur on his paws under any circumstances, he just goes ballistic if we try. Doesn't mind the rest of his body being clipped but will not tolerate the clippers near his paws. I heard that Melatonin calms a dog down, but I wonder to what extent. I reckon he'd have to be near comatose for us to be able to do it.