I learned and davened the early shift (netz) in an aguda that is (was?) or at least acts as a wealthy community. Three of four mornings a week, a crew of Russian emigre seniors (as many as would fit in a large car or two) would come and make the rounds during pesukei dzimra. This was a minyan of @ 30-50. The accepted donation was 1$ or fifty cents each. They would then do other minyanim, and later, visit some “hot spot” homeowners, or home businesses. I worked as a craftsman in the same community, and often was left alone by the homeowners. Occasionally, I would answer the door to see my “friends” from the morning . If it was a single one, I would give another dollar. If they came as group, I would tell them that I cannot substitute for the shul, or for the homeowner. These were all carriers of Vaad cards. How efficent the Vaad was I don’t know, but they did sometimes post faces, names and M.O.s of the frauds.
What disturbed me, was the occasional, and always Rosh Chodesh arrival of Chassidishe collectors, in groups of two or three, who are collecting for the same cause, but dont volunteer that info unless pressed.