Application appears to have been evenly split between outdoors and indoors.
Outdoor applications were broadcast treatments typically made to the near-ground portions of buildings and tents, and other places where the target pests congregated. Indoor applications probably included crack and crevice treatment, as well as broadcast treatment of floors. During crack and crevice application, a stream or cone of spray is directed at cracks and crevices, such as commonly occur where a wall meets a floor. Investigators assumed surfaces adjacent to the cracks were treated, and that overspray could have been substantial. Additionally, building size, condition, and configuration impacted the relative fraction of surface area treated.