As for permethrin, let me give you one of our odd experiences using it. We treated our clothes with it during a Costa Rica trip once. Mike, myself, and a few others were up on top of a mountain rapelling down a waterfall. Of course we got soaking wet. After going off rope and getting back in the dry and sun, Mike started to develop an allergic reaction to the permethrin and had to remove his shirt and wash off before getting better. Not being sure if it was the permethrin he put the shirt back on and the reaction started again. So, we're not 100 percent sure it was the premethrin but since then he has not been able to wear any clothing treated with it. No one else was bothered by it. Anyway, since that time we have advised all of our jungle participants of the "risks" associated with using treated clothing.
Jeff Randall