Chaparral is labeled for fescue seed head suppression. The Dow website has some information about it.We have never tried it or know anybody that has locally. We are planning on using it on our electric fence rows this year.
Intensive grazing works very well for seed head suppression and only cost the time of moving cows.
There's a guy in Patton that claims it's working, but he also says it will turn the grass a little brown. I don't know anyone else that has tried it. Sounds like a great thing if it would do that and not stunt the leaf too much. I believe that I don't have enough cows to be effective, and running a 8' bush hog over it after a rotation gets tiresome and expensive, and sometimes need to clip it before they move that much. I have a couple of patches that go to seed every year.