Sorry it took me a while to respond, I was distracted by other issues.....
Actually, the magic word is Cavra-Poo-Davra. That stops them. If you say what you typed they get wings and THEN you do have to worry about them flying.
A little history on the Cavapoo.
The breed was actually bred to protect Cave A Vans from polar bears. That was a serious issue at one time BTW. The breeders had lost a LOT of wine that the polar bears were replacing with Coca-Cola and the vineyard owners were NOT happy. They combined the two breeds of dog because they thought combining the pure unadulterated ferocity of the cavalier spaniel and the poodle's natural love of and protective instinct for wine would make the perfect anti-polar bear dog. Well, the proof is in the pudding and when was the last time you heard of someone finding a polar bear in the cane a vin? Most certainly it is not since the introduction of the cavapoo breed.
Here is an image of my Cav patrolling against polar bears.