My keets are *very* excited when the see wet greens coming their way. They are usually very cautious with any new object (To the point of, when being offered millet by my left hand instead of the right, they wouldn't come near. They were scared of my wedding band).
Anyway, the very first time I offered them curly kale, they couldn't get to it fast enough. They dashed over and drank the water drops, nibbled and rolled around in the kale.
So maybe some dripping wet greens would be a way to entice them.