I have used permethrine on clothing once when we went to the Amazon and seemed to work. Normally I'm a magnet for mosquitos and never got bitten (put on DEET too). Had also the problem of not finding a solution ready for spraying on the clothes and ended up going to the pharmacist, got some permethine solution and diluted it in water in a 0.25% concentration.
Peripel seems to be 0.19% and there are other products on the market like Nomad Bugproof and Sawyer Permethrine that have 0.5% concentration which it might be too much, that's used for the military. No-one seems to really know the exact safety threshold but from what I've seen around 0.20-0.25% seems to be the consensus for normal civilian use considering that this stuff actually is an insecticide, toxic in high concentrations and absorbed by the skin.