Use whatever has the most deet in a spray bottle, areosol is what fucks up your guns when you miss and spray your goggles and gun. If you use a spray you can spray into your hands and then rub it on. I havin't noticed much melting on my guns/goggles because of deet, then again its not a huge deal to me since I don't baby my gear.
Make sure to take your goggles off before applying the deet, essspecially if you still use an aerosol, I see lots of people forget they have their goggles on their head and just spray all over themselves.
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