1) it’s usually a synthetic pyrethroid not an organophosphate based pesticide (usually permethrin)
2) a range of protocols are in place, including residue spraying (ie the aircraft is sprayed say weekly while empty), spraying before arrival while pax present, or a combination of both. The cargo holds are also treated but I believe that is usually residue based.
Anyone who thinks they’re not being exposed to a pesticide because a hostie doesn’t walk through the cabin with a spray can has missed an important point
also of course it’s not 100% effective but it’s deemed effective enough to make a significant dent in the problem, which is real and not imagined. Very little in this life is 100% effective and yet we still do plenty of those things. Antimalarials are a prime and relevant example. Do people not take them when going to malarious countries because they’re *only* 90% effective?