Back in the day when grandpa had herfords, he would toss a handful of fine stock salt in the eye!   That really made it water, and it really made the critter howl!   Almost seemed inhumane..but it worked!

We use LA200, a patch if necessary or else stitch the 2nd eyelid shut.  The eye stays stitched for a week or so until the stitch deteriorates.   We had a bad outbreak last winter in backgrounding calves as well....it was not pleasant.    We do vaccinate the calves at turnout and usually have no trouble.   We did have a couple  calves that did get it this summer though.