there is one way that I have seen work. Mow it down when it sprouts in the spring. When it sprouts again, mow it again. Do this about three or four times. From that point on, use a round-up type herbicide as soon as the leaves on the new sprouts open up. It may take a year or two, but this seems to work.
I've been told by folks that is you can fence off the area and let some hogs into it, they will kill it. I saw this once and it seemed to be working. I would be worried about tramp metal, nails, etc. it is around old buildings being ingested by the pigs.