Instinct and DEET

I would say any watch would probably be affected one way or another. On the bottle of deet that I have, the deet is actually melting away the cap of the bottle, pretty badly. This was kind of a wakeup call for myself to stop using it. If it's melting plastic, what's it doing to my clothing/skin/watch etc.?

I don't know if it's necessarily DEET that would cause harm, but I wouldn't use any type of insect repellent that could make contact with my watch.