In boxing it mean a straight punch (as opposed to any variety of round punch). A straight punch has considerable power and can do more damage.
An 'assault prank' where the victim is hung by his pants, usually by affixing them to a wall with nails. Compared to pants hung on a clothes line only with the victim in them.
In my personal opinion, and from what I've observed, it has the same effect as vertical lines, it makes the wearer look thinner but it does not make the wearer look tall or long. But all in all, it...
With clothes pins or you risk the clothes falling on the ground. You need a warm, breezy day for clothes to dry quickly or "effectively". Make sure that the clothing is spread out or it will not dry....