As you know, blam, anthropo-bio-cauldo-entero-galaxospherical type dude you are: bugs develop immunities to human-developed toxins real quick.
Study was done at HARVARD about 10 years ago showing human head lice here in the US were no longer killed by our Pronto, Rid, etc. They'd developed immunity.
Lice can't be gotten rid of short of a GD turban, anymore, once it sets into a elementary school group.
Thanks, didn't know that.
Well, gee, I didn't need Harvard to tell me that (two kids through elementary school) I hear toothpaste does a pretty good job - is flouride a pesticide?