PAM's active ingredient is permethrin, a pyrethroid, which is used very often by farmers to help control biting insects on livestock, and also on alfalfa and corn fields. I have used PAM, and it works very well. I have also bought a permethrin concentrate and diluted it down to 0.05% (same concentration as PAM) from the 10% concentration it came in, and it seemed to work just as well. The only difference I could see while using it was the PAM had a much finer spray than the spray bottle I used, so probably had better coverage. If you have a ranch store or the like near your house, they should carry it. If you do use it this way, just be sure you check the concentration of the permethrin, and you dilute it down to 0.05%. I paid like 8 bucks for enough permethrin to make about 6 gallons of 0.05% concentration (way more than I'll ever use ).

-Evan