The idea is to push off the ammonia. Due to a horrible drought this summer, I lost most of my crop, but I did salvage about four oz of Virginia Gold. I dried mine about four days in the barn. Ha ha, it's funny to write that I actually hung an armfull of leaves in the barn, but none were left on the stalks, as they all were lost on one day without watering. But, they dry that fast. I was just going to age cure them in jars, and open the tops every week to allow the ammonia to escape. And, then put them in sealed jars to age further when they get to a cured state.
I was going to build a flue. Run them through a paper shredder when dry, and then make a large barrel flue that rotates, but with only the small gains that I had... I'll probably build it next year. But, even doing all of this all naturally, there is are many reasons to use some sort of casing. A bit of honey or a tincture made from the fragrant flowers can reduce the chances of mold and will give it a better burn.
I've found several references in old texts and even in Native American literature on kinnikinnick, that they did include a casing, whether from the tobacco blooms, berries, or maple syrup, adding a carbohydrate really helps the burn rate.
I am getting ready to install an irrigation system to prevent losing another crop, but I expect that it will probably take me four or five years to be able to start smoking my own Virginias. There are many people that still grow their own, especially in the South, but the older folks case the hell out of their homegrown. I think that folks growing for a "pure" Virginia experience is a very new thing. ...at least this is what I have found.