Most waterfowl hunters purchase a commercially made wooden or composite duck and goose decoy to lure their favorite species into shotgun range.
However, some hunters do apply the old-fashioned mouth call technique to attract birds. My first experience with this was while hunting with Cree guides in James Bay, Ontario, in 1988. In Wisconsin, three extremely dedicated water hunters successfully used a purring or rapid tongue flapping technique to consistently call diving ducks.