We've discusssed this before. Here is what I've previously written on the topic:

I have a small business that processes natural fibers for fiber artists and handspinners. The clothing moth is a common topic of conversation.

Clothing moths and their larvae (which do the actual damage) do not like light so a dark closet hung full of wool kilts is a perfect haunt - especially since kilts offer even darker hiding places under pleats. Clothing moths are attracted to the scent of the lanolins, body oils, suint, etc in wool. For this reason, lavender sachets, cedar, etc are used by some to mask the natural attractants. From my reading on the topic, the efficacy of the sachets has not yet been confirmed but it smells nice and can't hurt. Clean wool is not as attractive to a clothing moth as a freshly shorn fleece in a wool pack. Your sweat and body oils will also attract the moths to your kilts.

So, the recommendations that I can make are:
1. wear your wool kilts regularly;
2. keep the closet door open and periodically move your kilts around (see number 1) paying close attention to the areas under the pleats;
3. for longer term storage put them in a tightly sealed chest - doesn't have to be cedar (store only cleaned wool in the chest).
Cedar, lavender, and other strong aromatics mask the odors of the things that clothing moths are interested in - they don't repel.