I wouldn't mind trying it, then. Well, with less of other people's spit, that is.

Polynesian custom often has the young ladies do the honors.

It's has a pretty mild effect. You can buy it legally in person at most places that would have it.

You generally make it by grinding up the root (or just adding the powder) and mixing it with water. It's sometimes pretty bitter, but you can chase it by chewing on coconut.
So yeah, no need to swap spit.