I also have used the afterbite stick for years on itchy bites. I also use windex when I am out of it... LOL! The ingredient that is in the stick is ammonia! I guess the "Big Fat Greek Wedding" dad was right! (He used it on everything and called it a miracle cure all, remember?)
As for a natural spray for the bugs not biting you? I don't know any. I have heard from hikers that if you eat banannas the bugs don't bite you. The potassium is offensive to them.