as a last resort then putting them in a pen with a sheep does work, best to do it with a ewe with lamp at foot as she is very protective over it. I did this with one of mine some 10yrs ago now, she was 2 or 3 at the time night mare for chasing sheep and cows, after a visit there with the sheep she never bothered again and still doesn't.
The second lurcher I had I got from a pup and took her in the field with the sheep and if she showed any interest in them at all give a quick jerk on the lead and a stearn 'no' and that did the job, far easier than the other method