Pyrahnna, Bronco, Dumor, none of them will fight the flies we have down here. I use the Dumor spiked with Deet. It helps. I also ride with a face mask with ears. Horseflies, stableflies, deerflies, and gnats. And then you have to remember the ticks. And the spiders in your path.
Oh, and I almost forgot. The hornets that follow you along the trail trying to pick flies off of your horse. That makes for a real calm horse.........
Dang. I just realized that I'm not looking forward to middle Georgia in the summer.