I think there is a more direct sense of clappers, relating to percussion instruments used in dance in many periods, including ancient Egyptian-derived cultures:

“Then, at a given sign, the middle of the hall was taken by a man and a girl dancer, who were provided with clappers. These were made out of two small pieces of wood round and concave, located in the palms, and gave rhythm to the dancing steps when suddenly knocked together…

http://www.bdancer.com/history/BDhist2b.html