<<Disclaimer: Verify this information before applying it to your situation.>>

GF:
Buzz Away from Quantum (I verified with manufacturer 5/99)
Banana Boat Bug&Sun (I verified with manufacturer 5/99.  All Banana Boat
   sun products are gf EXCEPT Aloe Vera Thera Body Lotions)
Cutters
Melaleuca Oil
Bug Button (wearable)

Many reports of Avon's Skin So Soft as gf, however, when I called Avon
they would not confirm the GF status and were not particularly helpful.

Other ideas:  Take brewer's yeast orally, rub cedar needles on the skin

One poster mentioned Coppertone products contain gluten.  Did not confirm this.