I gave up on mothballs years ago, I hate the smell as well, an arrow that seems to have lost the smell on the fletching will start stinking again if you are out on a humid day.
I changed to borax years ago.
I have so many ground wild turkey feathers that I quit keeping what wings people give me now and give them to a friend.
I did send them to Custom Feathers to be ground on the halves, he trades primaries for fans ad secondaries as well. The lady he sends them to to be ground has RA and has been unable to grind feathers as the condition of her hands worsens. He wanted the secondaries cut off still attached to the skin flap, boraxed and dried with the quills intact.
I have an ice chest I put my clipped off primaries in, I cut them of the wing with a bandsaw. Once in the ice chest I give them a good sprinkle of borax, I shake the ice chest every now and then to redistribute the borax, no bugs.
I put my ground primaries in a huge ziploc bag, throw in about 1/4 cup of borax and give the bag a good shake, no bugs, ever.