Sliding Polished Stones across the ice with Brooms to sweep the path to the target was the Winter Sport brought to Canada from Scotland.
Curling in Canada is also historically aligned with the military, so My ASL Dictionary has a Scottish Curler in a Military uniform (this time with a curling brush behind him) illustrating the ASL hand sign for CURLING.
The S hand is held near the body to push upward and open into a Slanted 5 hand, like releasing the curling stone to its target.