Never watched it before and had no idea what it was so sorry if this offends anyone...
...but when I turned over to watch The Olympics the other day and 'Curling' was on there were genuinely a couple of minutes when I thought that the caretakers were on sorting out the ice. I even turned to OH and asked him when it started to which I got a blank look.
I'm probably just incredibly thick but it did look like very fast 'sweeping up' to me.
*disclaimer* I know nothing about sport!