You are better off using Concussive Blow II than Flashfreeze because of the long recast of 1 minute on it. Also make sure you are killing the male/white antilopes and not the female/blue kind. I remember back in the day there were lots of ppl saying the only way to obtain the horns was thru Goldsmith leves because there was no way to incap and make the horns drop, well sure there is no way you'll ever see a horn drop if all you are killing are blue antelopes and not the ones with the actual horns on them ._.