If one stops at a peasant's hut and asks him: 'Gospodarzu, mata może świże jojka?' Is that regarded favourably as 'he's like one of us' or would it be seen as taking the p*ss?
As someone who has studied sociolinguistics and anthropology, I'd be wary of doing it if you didn't know the people. Others might feel insulted that you don't think they can speak 'proper' Polish.
Some people might wonder why you were trying to use their dialect, others might feel threatened (they might use it to keep outsiders 'outside'). It also depends on how well you speak the dialect, as the reply might be too much to handle.