Does not sound good...sorry.
I have no idea of the plug type whether it has a washer of a chamfered shoulder, for the type with a washer I was taught to screw them in by hand until I felt they had hit "bottom" then give a quarter turn to compress the washer.
With the shouldered type again the idea was to feel the thread starting correctly and screwing in by hand you would feel if it had perhaps started incorrectly thus less chance of using force to cause things to cross thread... once the plug felt on it`s seat then torque to the required setting..
