That is interesting and somewhat strange.
It is made in Mexico, but so are many Duncan products.
I don't know what Cua Cua stands for. A brand?
If you accent the A in "cuA cuA" it would be the sound that in Spanish is associated for a duck, and it would sound like a joke.
If you accent it in the u, cUa, cUa, it does not mean anything in Spanish and sounds weird.
A search on google only gave me one on an Ebay-like listing in Peru. Perhaps it was made for that market and it is a native word.