If it's duck down, it's not completely formed when it passes through the water, so it's difficult to spin it through. If you rotate by hand, if there is still water on the surface, it means that the rotation is not complete. If you hang it like this, it's easy to form marks. I suggest you wash it with warm water again, add about half a lid of white vinegar to the washing machine for the last time, and twist it hard after turning. If there is still water on the surface, it is easy to form traces.