You are polarizing the generator, not the regulator.
Any time a generator has been serviced, or replaced, or the vehicle has been stored for an extended period, the battery polarity was reversed, the generator must be polarized.
What polarization does is establish a residual magnetism in the generator which matches the polarity of the system.
Speaking of polarity, the original regulators used to be specified as positive or negative ground. Not so anymore. Reason was the difference in alloys in the contacts was used to get the longest possible life from them. Now they use cheaper, nonspecific alloys. Saves a few pennies, reduces stock on the shelf.