You could always go old school, before mothballs the standard remedy for moths was to get some cedar chips or planks and store them in the closet. The oder is very nice but supposedly it repels clothes moths. Evey 6 months to a year lightly sand the cedar planks to expose fresh surfaces to restore the odor.
If you do use mothballs I prefer the naphthalene variety. They are harder to find but I prefer their odor to that of the paradichlorobenzene type. Possibly because of the association of the odor to the other common use of the chemical. It is what the odor cakes in men's urinals is made of. I don't care for the idea of my clothes smelling like a urinal.