Spiral hoar frost and spiral device around telephone or electric landlines
Depending on exactly how they are configured, this is probably a spiral vibration damper:



Image from https://powtech.en.made-in-china.com/product/wbpQcvdJCXYa/China-ADSS-Spiral-Vibration-Damper.html

From what I understand they are useful on smaller cables, to dampen high frequency oscillation from wind, and cheap to install.

I can't answer the part about spiral frost. Maybe the frost forms on the spiral and is then slowly dragged down by a combination of gravity and new frost forming, helped along by the constant tiny vibrations from wind. It would still remain in the shape it had when it formed.