B767 Captain laments flight manual go around procedures that he believes are ambiguous; and elects to use previous procedures until clarification is received.

Narrative

The FAA-Approved Airplane Flight Manual describes an ambiguous go-around procedure. It requires the non-flying pilot to check go-around thrust. However; full go-around thrust is not customarily employed and the manual provides no reference as to what thrust value the non-flying pilot should expect to see. Furthermore; it is silent on what the non-flying pilot should do if doubtful about the thrust setting. This could easily lead to both pilots manipulating thrust with the pilot flying confused about the actual power commanded. The procedure further requires acceleration to a high airspeed during the go-around maneuver; a challenging process in the best of circumstances. After lengthy discussion during cruise; it was clear we could easily get into trouble trying to approximate a procedure we didn't fully understand. Exercising my emergency authority to ensure safe operation; I required the First Officer to brief our previous procedure and will continue to do so until training resolves ambiguities and establishes confidence through multiple repetitions in a flight simulator.