Cigar Asylum Afghanistan

Hey quick question. I am trying to expand my cigar storage capability by building a field expedient humidor out of an ammo can. It is air tight and I am using a cedar cigar box to line part of the ammo can (cedar is hard to come by here). I have some humi paks but I don't have any distilled water. I have sterile water, does that work? Do I need to line the whole can with cedar? It is presently about half full of cedar. What is the best way to gauge the humidity level? Thanks for your help.

SEMPER FI