OK, for this camp, I've searched out the Bushman's products.
There is one cream that is 80% DEET by weight!!!! OMG, put that on and stand next to your eyepieces and I reckon they'll dissolve in the fumes!
I've bought the spray that is 20% DEET. I'll use that on clothing (up in the cabin area, of course, not on the field!) Then I'll use Tropical Strength Aerogard roll-on on exposed skin, down on the field. That's about 10% DEET. But be careful to keep it away from front of hands and around eyes - anywhere that might come into contact with eyepiece rubbers, keyboards, mobile phone, spectacles etc.
But I'll still bring a big bottle of Stingoes in case prevention doesn't prevent.
Best laid plans.......... we shall see.