Sep 05, 2013 - 07:28 AM
Riptide Insecticide Concentrate is the best pyrethrum based product. Probably not the best, but it will work. It will also need continual re-application to remain effective.
If you want longer control, then consider using a microencapsulated product such as Demand CS. Demand CS is a type of synthetic pyrethrum that gives much longer control.
Don't use a pressure washer when applying insecticides. It dilutes them way to much, and basically you will get watered down insecticide.
Pressure wash the house first, then mix the insecticide in a spray tank, exactly according to label directions, then spray the siding by hand.
Hope this helps.