Well, you gotta call in the ducks really, really close. Don't expect penetration of the shot beyond the distance of the powder smoke discharge.
It also works well for rats, but the the trouble is getting the rats loaded into the throwing machine.
I took a herpetology class back in the late 80s. The instructor always started off class with some sort of bizarre stories. More often than not, the story was some stupid human trick. Several of the stories were wehre people peppered their own feet or legs, or those of a buddy, when encountering snakes. It is not wise to try shooting a snake that is between your legs. With these little shot shells, you could get enough spread to hit both feet at once!
I have carried shot for snakes on several trips out into west Texas and New Mexico and never had to shoot a snake. Usually, I just end up picking a target to demonstrate to a buddy just what sort of crazy spread comes out of a .45 acp shot shell from a 3.16" Kimber barrel. I keep buying the stuff and it ends up just being a novelty. Of course, I like to look where I am stepping BEFORE I step.