Maybe you guys can just organize a casting session in a park not necessary direct to fishing. So that the new comers can actually concentrate on the casting rather than the catching of fish or line landing in the water. Just an hour of casting in the park one weekend morning or something would be good.
Fully agree with you about casting session in a park lawn. Most people would enjoy more getting the line wet in the water, and if luck is there, a fish on the fly too.