Cedar chips won't kill moth larva:
Does Cedar Actually Repel Moths?
Does Cedar Repel Clothes Moths?
Purchased materials should be OK. Store them in separate zip lock bags.
For harvested materials like feathers, I freeze then for about a week to kill the larva and adult bugs. Then take them out of the freezer for about 3 weeks to let any eggs hatch and refreeze for another week. Do a second cycle and you should have no live larva, bugs or eggs left. No nasty chemicals either.