Q: Should I break my harp in?

A: Some people say it’s necessary, some people say it isn’t. Anyway it
couldn’t hurt to play softly at first and don’t bend the notes too far.
Then after the first hour of playing or so you could start playing harder.
This could lengthen the life of your harps — BB

Some purists take a new harmonica apart and re-tune and re-gap each reed to
optimize it to their playing style before they even start to play, and then
break it in (more on this below) ! — HA

Others finish the reeds in a special manner to minimize transverse
scratches and thereby prolonging life. Pretty involved — HA