that was basically how I trained my lab...I also didn't give him treats (or people food) unless it was for bringing an anter to me....made him want to do it that much more...now that he has it down and has over 100 "unasisted" (ones I wouldn't have found on my own), he gets spoiled and gets treats all the time!
One other thing I did was before handling dropping the antler or playing fetch, I would rinse the antlers in water to make the scent stronger, and used laytex gloves like Shed Stud mentioned.