As crazy as that last photo looked, here is the first "knock down" photo.
Here is how this look is achieved.
I simply mixed fuller's earth with water until I got a VERY runny soup. I then slapped it all over, trying to get in cracks and crevices. You natural inclination will be to just brush across the high points, but it is really important that you get down into the deeper areas and recesses. Since I live in AZ and it is burning hot out here right now and it dries within minutes. It is also important not to do 100% coverage. Trust me, when it dries, it will go EVERYWHERE anyway, so don't worry about open spaces, they will get dirty.I spent a lot of time on the neck, really trying to cram dirt down into all those stitch lines. takes some time, but there it is.
One dried, I took a bowl of water and a flat scrub brillo, like you might use to clean your rims or your grill, wet it, slung it out, and then GENTLY took one swipe across all the high surfaces. I didn't bear down and I didn't do more than one swipe. This knocks down a TON of the dirt.
From there, I take a sponge, wet it, and then wring it out and lightly go over the high points again. Then, because I caked up so much dirt on the lips of all the armor, I hit that with the sponge, cleaning and rewetting it often. Again, you are going to take off almost everything you put on. You only want traces left.
You will notice that almost all of the armor has a film of dirt on it now, with some of the low areas still having a heavy/solid accumulation. I go back, getting more and more random and hit the high points with the sponge again until I am happy.
At this point, the fuller's should be completely dry so you can go back, gently, with a dry soft brush and brush away any really heavy clumps from the recesses. You really only want to leave the recesses with a slight amount more dirt than the high points.
Next, I dampen my hands and just grab around on the armor randomly. This rubs a few places almost clean, and smears others in a way the sponge did not.
Finally, I come back in with some dry fuller's and touch up any spots I am not happy with. In this case, a lot of the vest seemed just a little too clean, as well as the sew lines in the strapping. All of these got a heavy dusting.
I am not sure if I am totally happy with it yet or not, but from here, you can "set" the dirt with hairspray. Note... once you do this, it will be VERY HARD to ever get it back off again, so be sure you are happy with it and go light with the hairspray.
Anyway... I am still debating whether to go at it one more time before setting it, but this is where I am at right now.
PS: Always remember that a delicate touch is important but it is equally important to go heavier than you think you should as so much of this dirt and weathering will be washed out in con photos and you will barely look dirty at all.