we were basically offering cat take-out

You just need cat's humans to return your traps, like one of those coffee places with reusable to-go cups, and this is a partnership LOL (Love the kitty's jaunty little white tail tip!)

A friend "paid" his cats with bits of cheese for bringing him mice and pack rats caught in the property sheds, walkout floor, etc.. One clever kit found a rat that one of his traps had caught, and carried rat & trap to him. A. thanked her and gave her cheese, because the deal was, rat=cheese.

Very satisfying conclusion