I tell you what I know some good medicine for bad brair thicket or any vines for that matter. A good dose of fire about mid January will cure allot of briars. Find a good natural fire break and light it several hunred yards up wind from the break about mid morning with damp ground and a steady 5-10 mp wind is perfect so it don't get away from you. Just light a match briars burn quick and sure helps clear things up and even makes good deer habitat for the next couple years, so the goat hunters will be happy as long as one of their deer feeders does'nt jump into the fire.

It was not uncommon while hunting when I was kid after the dogs were caught for the old men we hunted with to take out matches and just set a patch of woods on fire. The ground is damp and grass is grazed to the ground by the cows so you couldn't burn the pasture if you poured gasoline on it. The trees tops wont burn because there is no leaves on them but the briars are dry and burn very well.
Waylon