What brand of hose are these? Are they real wool, or a wool blend? You mentioned elastic at the top; I'm not sure I've come across any kilt hose that actually have a stretchy top.

If they are real wool, you might be able to shrink them back down with warm water. For obvious reasons, this can be disastrous if you use water that's too hot, or if you agitate the wool too much and start to felt it.