I wonder why no one has ever asked about this before?
Pure fact:
DEET has been determined by the US Military to be the most effective preventative.
DEET in and of itself is not harmful to plastic material- what causes that effect is the inert material that it is suspended within. If you're not sure, spray it with extreme care. Yes- keep it off of your salad.
High percentage DEET is not necessary. They higher the percentage of DEET, the longer it is designed to remain on your body and working and not be washed off by what is considered to be normal human perspiration. Depending on your dive schedule, you may do just as well with the lightweight percentage DEET (cheaper).
Sand Flies (Sand Fleas, No-See-Ums) feed in still air, near moist decaying vegetable matter, around the hours of dawn and again about 1630 hours. Stay out of wooden sheds. Certain areas on the island are more conducive to their habitat.
I spray myself incoming at the airport if I'm going to be there longer than 5 minutes. I also keep a can in the dive locker area (warm, dark moist wood~ sounds like primo space for the little buggers) and we keep a can near the door of our room before exits.
But the question was... "
Looking for any and all remedies " That asks, what do you do when you've been bitten?
A little dab from a q-tip. Instant relief.