Do you mean like kicking sand in your face!!
I think this is just a thing that they do to spread the word, so to speak - it doesn't help, however, if they have done a poo, you are bending over to pick it up, and you get more of the same shucked back into your face !!
Barley does this, and I tell her just because she may have seen her friends do it, that is no excuse !!