The zinc oxide works great! I've tried other sunscreens but they don't cut it. As for the halter, I agree with everyone else, it's dangerous for your horse to wear a halter 24/7. I did not know that until I experienced it myself. If you have problems catching your horse (as I did) get them into a routine. I put the halter on mine when it was time to eat and put him in his stall, then took it off and let him eat then back on again to turn him out (without his halter on).