@Dada007
I think the technical difficuties involved in "green screen" filming of an active shower would make this impractical. The water droplets would take on the colour of the green background and would be removed along with that background only to magically reappear when either hitting or passing in front of the model's body or, worse, would be impefectly removed giving the clip a very strange look.
We will have to be satisfied with the existing "glass" clips where foam is used instead.