Nomad, I am sorry to say we spent a fortune on a service that used a non-toxic-to-humans powder to dust every surface in the 2-story loft apartment. This meant removing every stitch of cloth from everywhere and storing it elsewhere for several days while the powder did its thing. Then someone (me) vacuuming up all the powder, laundering all the fabrics, and rebuilding the whole living space.
Two days later, more moths. This is when we realized they were coming up through the HVAC.
I also learned something interesting from the guy who did the treatment. He said to ask the neighbors in our building if they too were seeing moths because, he said, "People will lie about roaches and mice, but not about moths."
Also learned that while wool and cashmere are their caviar, there is almost no natural fiber they won't nibble.