Any insecticides applied on outdoor surfaces will eventually be removed by breaking down in sunlight and/or washed away with rainfall. Tri-Die contains natural pyrethrin, which breaks down quickly in sunlight, and silica gel, a natural dessicant that would likely be washed away quickly. The PBO synergist in the product also breaks down quickly once applied. We are not sure why the product would need to be removed from where it was applied, but you can always use a hose to water the area to remove any residual product.