In reply to DaveHK:
I use the Sawyer Permethrin. For the most efficient use of it, I put the clothes in big zip lock bags and pour some in then squish around and leave for a couple of hours.
You can then squeeze the clothes into the bottom of the bag, put them out to dry and put some more in the bag. Seems the least wasteful for the most treatment where you need it.
I also spray a few things that don't need full treatment (like other trousers below the thigh), arms of a few tops.
Don't forget, before the stuff dries, it can kill cats. Once dried, even when rewetted, it's safe. (I'm still careful with wet treated clothes though).
I treat socks, trousers and spray trainers/boots. I also do a couple of tops that I know to wear if I'm going somewhere really bad and doing something where I'm close to the ground (photography for instance).