In general yes, I think improved UI can guide user behaviour to more desirable outcomes.

However I don't think it's as simple as changing the button text. Even a process driven UI, like a wizard style interface where you have to click next to progress through each step might work, but users very quickly become immune to dialogs. They don't read them, they just evolve the actions that get them to their goal the fastest, and the users goal does not include reporting their spam.