I am getting conflicting advice about winterizing my motor (90hp
Mercury four-stroke)

A friend told me that I need to run the engine "dry" for a few seconds
so as to eject the water that is still left in the impeller after the
motor is pulled out of the water.

Others claim that when the motor is pulled out of the water ALL water
automatically drains, not to worry, and that I should never, ever run
the egine "dry", even for a few seconds.

Who is right ?

André