I keep a few in my pocket to distribute to children, as occasion permits.

Many, many years ago I was in the hospital for something unimportant. Wart removal, or something. Memory fails. However, I was disconsolate and acting like the child I was. A stranger, a soldier, gave me a 10,000 yen(?) note. I was entranced for hours and quite forgot my emotional upset. ^ to that stranger. I still have that note ~40 years later.

A few years back I had some Australian dollars left from a trip down South. I left them (along with US currency) as a tip at an Outback Steakhouse. Listening to the server discuss her find with her co-workers was reward enough.

I'm sure you can find a use for your coins that will far outweigh their value as currency.