I think if you were to put a liquid sanitizer onto the pills they would just start to dissolve.

Can an you go to your doctor or the pharmacist and explain the situation? You can even fib a little if you don't want to explain your phobia and say that they spilled out somewhere dirty, like a hotel floor or something. Maybe they can do a swap right across where you get the exact amount you give them back, so they know you're not abusing them but that way you can get clean ones.