Better to ask "is everyone here town" than specifically look for scum because it lets third party skirt under the radar.
I'd actually rather use it on groups of 3 scum candidates over "clear people who are townie" because if we mass-clear people we thought were already town, it's kinda useless if they just die. It's too early in the game to be playing for PoE imo so I'd check 3 suspects and see if there's at least one scum there.
That being said I fully expect to wake up and see M2H either dead or immediately eating dayvig. I don't see them being a liar with someone else supporting their claim with the second QA.
I think nuxl is the least townie of him/tommy/hal rn but im not sure if I'd want to double dip in the lynch pool or not. We have plenty of time so I'm gonna sleep on it.