Optimal way to clean Lightning port?
Since Apple doesn't have any official, public-facing support documents for cleaning Lightning ports, you may be straying into opinion territory.

Users have reportedly successfully and safely used paperclips, plastic or wooden toothpicks, compressed air, vacuum cleaners with a hose, and even tightly rolled sticky tape. Paperclips and other metal objects reportedly have the ability to damage your iPhone's Lightning port pins and some methods are allegedly better than others.

Whatever you use is up to you, provided you can maneuver the object in a way that you don't damage the port's pins.

(Sources include Reddit and Stack Exchange, but answers are anecdotal.)