Divided by a common language

In the What Are You Sewing Now thread, I noticed the Australian gals using 'snap' the way I'd say 'jinx' -- for when two people say or do the same thing at the same time. The rules around jinx vary but commonly as a kid you'd owe the person who beat you to saying jinx something like a soda. I never saw that debt actually paid. Are there rules around 'snap'?