Dick, I have in front of me a bottle of "Cutter Advanced" insect repellent, and a bottle of "Off familycare clean feel" repellent, both of which have PICARDIN, rather than DEET, as the active ingredient. They are every bit as effective as the DEET products, and are harmless to compass and watch crystals, stock finishes, plastic turkey call parts, deer grunt calls, and all the other hundreds of items that DEET has melted through the years.
They smell good, and do not leave that oily residue on your skin like DEET products.
I find mine at the local WalMart, NOT in the spt. goods section, which contains only DEET stuff, but in the area of the store that stocks household chemicals like cleaning products and the like.
Try it - you'll like it! If it works in the Southern Swamps during spring turkey season, it should work anywhere.