In the '60s and '70s, people played like crazy with two small heavy balls on a string. "Clackers", once set in motion, made an ear-splitting clacking sound, were super-fun, highly addictive, and sometimes would explode. So, of course, they were super-banned. I remember the bruises on my wrists and fingers as I tried to master the art. Unfortunately, at my "lovely" Knoll School for Boys in the UK (High School), the clackers would also be cracked onto one's unsuspecting bonce (head) in the playground by the bigger kids.
Clackers are mentioned in Pink Sombrero. Scary 'businessman' Armardo Lopez refers to them in the confessional box when sharing his chagrin with the priest. Armardo had been put through various fascinating fertility rituals for his wife to conceive a son and heir to his throne. He presents a beautiful motivational speech to the Rabinos priest—it's all to do with the Clackers!
I came across a nice orange pair of clackers in a local store in Mexico. An excellent gift for a friend or relative who takes a vow of silence and joins a Buddhist retreat or enters the Roman Catholic priesthood.