I have no idea what plant you're referring to, and I've certainly never brewed with it. I'm the last to shy away from nontraditional brewing herbs -- I've made a good couple of gruits along the way, but I'd wonder that if you brewed with and/or drank something made with any significant quantity of this.... Well, just listen to your description: "...there's a short but intense increase in saliva production..." If that effect continues throughout the gut, you might be looking at some intense diarrhea...
Do you know the real name of this plant/herb?