Watch permethrin, , the synthetic version is poisonous, and the natural is still very irritating to sensitives.
Best bet is boric acid powder, if you can use it without inhaling any. It is less poisonous than salt, but will stick in lungs.
Do backpacks and hair, and it will fireproof em too !
Tea tree oil is ok, but stlll tough on sensitive skin too, haven't had that great of luck myself, tho at least it doesn't smell like neem oil.
Can use cinnamon oil while you are waiting to find other stuff. It will kill most everything but MRSA. keep it out of eyes and mucous membranes.
search on site here for boric acid, you will see hysteria and my links too.
http://www.health-science-spirit.com/borax.htm
Most will recommend diatomaceos earth as a dusting, don't inhale that either.
I havn't been able to get DE to kill anything except soil wildlife.