Not nearly as prolifically as Aziraphale; the Soldier's only done it once, so far. It's tactical, a source of potential information and as an experiment in communication. Plus, weirdly, the spirits don't actually freak it out the way people sometimes (often) do.

"I have no idea. It's the last thing I'd have expected, either." Well, not the last, but. Pretty close. "But it's easier than trying to use metal fingers on those whistle things."