Salaam aalaikum, Pa-khair-raghlay esta melgaree
My Pashtu immersion course is over. Ever tried to learn a new language? Ever try to learn a new language in two weeks? Whew! years ago I bought some cd’s to listen to in the car while I commuted thinking that I was going to learn French. The most I ever got out of it was “Hello? Marie? how are you? and Where is the taxi stand?” Pitiful and a waste of money in hindsight.
We were pretty lucky for this course to have a Professor that emigrated from Afghanistan in the late 70’s and is fluent in Dari but also Pashtu. He has been in the US for many years, understands both cultures and is able to convey what we might consider the idiosyncrasies of the Afghan culture. Just a good, and what we call salt of the earth fellow. Re-enforced in me that even with cultural differences there are good people out there.
Actually this is not a new thought, but have you considered a second language as part of your preppers tool kit? I am not saying that you and your family should be fluent in any regard but maybe have some predetermined words or phrases in the event of an emergency? GF and I use Alas Babylon (yes from the book) as one of our passwords.
I had a short email exchange with Archer Garrett a few months ago about getting home if myself or GF is caught somewhere in a SHTF event away from home.
Something that I never really considered was a point Archer made about having certain way-points on the route home or to a safe place and having a Sharpie to scribe on a wall or door that “I made it” or “heading east to Dad’s house”. Take that last thought and add the second language skill to the notes or graffiti left on a way point that you had pre-planned and very few will be able to decipher the code. Even the Lost Colony of Roanoke in 1590 had left a clue as to the where a bouts of the survivors “Croatoan” was found carved into a post left at the site of the original fort.
I think it is a pretty intriguing idea, Yes? Unless it is in Spanish I can’t foresee many people being able to follow your messages left behind.
Ad Parare 
If OPSEC is an issue on the route and everyone hasn’t learned Swahili yet, you could go the coded book route. Everybody buys a copy of a book and you reference letters/numbers/words/whatever using page #, paragraph #, letter/word #. Preferably one of my books of course. You could even use multiple books if you were so inclined.
Seriously though, preferably a book you’d already be carrying (bible / survival manual / field manual / communist manifesto / vogue magazine / the usual.)
You could develop a code in a matter of hours probably.