My opinion; great idea to do it, bad idea to say it out loud.
In a nutshell!
I find it somewhat distracting if an FO loudly runs through his particular pre-line up chant after putting away the before T.O. checklist, especially when it doesn't contain anything extra over what he has just finished reading out.
Fully agree that a quiet check of "the killers" is vital, and I will always pass on that advice.