Years ago when I first started buying tobacco in bulk from Craig Tarler I commented to him that his tobacco was very dry. He said "That's because I believe in selling tobacco and not water". He recommended hydrating it with distilled water or, in the case of Virginia blends (which I smoked exclusively at that time), good bourbon whiskey. I used to spread the tobacco out on newspaper and spritz it with Evan Williams bourbon (the black label, the green label has no flavor) from a spray bottle, stir it around and leave it overnight, spritz it again and mix it around (you get the picture) and when it got to a hydration level I liked put it in my storage containers. The process usually took a couple of days. Whiskey is a great addition to many tobaccos. I've never tried it but I imagine a good peaty Scotch would be great on a Latakia blend.
One does have to be careful though, if you mist it with distilled water or whiskey be sure to mix it up good and leave it to air out to where it feels just fresh (hard to explain but sort of soft like tobacco fresh from a tin and certainly not moist) in order to avoid mold. Dump the propylene glycol down the drain, I would never put that stuff on tobacco. A 59 cent gallon jug of distilled water or a ten dollar bottle of whiskey will provide you with enough hydration fluid to last many years.