I have flown in and out of the McAllen airport so many times. Years ago I started putting Triple Antibiotic ointment in my nose as a precautionary measure. My main thought was to prevent TB as I knew I was at a greater risk in a small enclosed place with people coughing. It should help prevent any bacterial infection.
Have you checked with your doctor to see if this is safe? I know it is not safe to put Vicks in your nose. I use MesoSilver in a spray bottle when I have a cold. It kills many germs. It helped clear my daughter of MRSA when she took it orally & poured it on her infections. I know many people do not believe in the use of liq silver but I've seen 1st hand that it worked. I also take it & have never turned gray.
Not a bad idea.