Dunno what the "hogwash" is about...
While you might get pendantic about his use of the word "axes" in context, a proper barrel roll is done in 3 dimensions. The visual reference is a point/object at or slightly above the horizon approximately 45 deg left or right of the nose. The object is to keep that point stationary on the canopy/windscreen as you "roll around" it. Acceleration felt in the airplane should never exceed 2 Gs, which is within the limits of transport category airplanes.
OTOH, it is easy for a novice to mess it up and "bury" the nose when inverted, get scared/anxious, and pull excess G to recover.