I do the pre-emerge every spring and fall and still had a good bit of it growing.

I sprayed it with Butyrac, 2-4db, what I use on my clover fields, and it knocked it out.

After it was dead I went around and sucked it up with the shop vac to get rid of all the spurs so it wouldn't come back and where we could go barefoot.

It's a pain but you can get rid of it.