Resmethrin, itself, is about as toxic as table salt to humans and pets like dogs and cats. Most aerosol insecticide spray and foggers are very good at covering large areas, places where your family and pets are more likely to touch than the insects you want killed. Insects are small and will live in the least disturbed areas where they won't be bothered. They will come out to get food and water, but will spend most of their time out of sight. When you spray with regular aerosols, you are laying a chemical minefield, hoping that an unwary insect will stumble upon it and die.
Time is on the side of the insects.
The powerful spray reaches deep within the insect's home, covering the insects, so there is much less waste and mess. Since drywood species live entirely with the wood they are eating, their colonies can never be larger then the wood. Their colonies are usually small, but there may be many non-connected colonies in the same area or even piece of wood. Drywood termites can be effectively treated with TERM-OUT . Just spray into an entry hole of the tunnels untill you see the insecticide coming out the entry hole or some other place.