things are certainly a lot different at various Societies. We even have a monthly meeting dedicated to 'problem' plants where everyone is encouraged to bring them in for open discussion. Even have a microscope that someone brings in specifically for that purpose.
Our society has a problem corner where people can bring sick plants in and get help. But they are asked to bring them in a bag so that the show n tell and plant sale table etc. are not infected with anything.
At our show we had an information desk to field questions and encourage people to join our society. But also the plant hotel where you can empty your hands and go buy some more or look at the displays