

On the first point, I read the original paper. It was wild and shouldn’t be taken as fact. The authors modeled a 3d penis and vagina and showed that the penis is able to scoop out paste from the vagina. They then interpret it as that it’s “possible” for the penis to have evolved the way it has to scoop out rivals’ semen.
The obvious counter to the claim is that anything can be used as a shitty scooping spoon if you try hard enough.
Also, note that a woman would need to have some wild body counts if she’s having sex so often that she doesn’t even have the time to let the previous guy’s semen drip out
Shooting is like driving a car. A baby could do it. Few can do it safely.
Using a gun is really easy. And I suspect school showers aren’t particularly concerned about safety, so that’s not an issue for them