Tips and Tricks. Put a strong solution of sodium hypochlorite (bleach) to a sprayer. A spurt stops any insect to its tracks in two seconds, and death comes in ten seconds. "Natural" insecticides, e.g. Raid, which are extracted from plants are often too gentle. Ants and flies can struggle as long as a minute, when they're killed with Raid. No wonder some insects develop a resistance for an insecticide. Sodium hypochlorite spray is corrosive(1 and strangling gas for the insects, so it kills instantly.
The hypochlorite ion itself is charged, thus water-soluble, and cannot pass through cell walls. But, it is easily protonated to produce hypochlorous acid, which is normally in equilibrium with hypochlorite. Hypochlorous acid is a uncharged molecule, and thus is soluble to fat, so it can pass through cell walls. Humans breath with lungs, which are well-protected against this by the upper respiratory system. Insects, on the other hand, breath directly through small ducts opening at the surface of their skin. So, hypochlorous acid can enter unimpeded to their internal organs. There, it enters individual cells and deactivates glucose metabolism, so the cell cannot live, as it cannot spend energy.
This has to be used in a well ventilated area, or in a place where air quality is not an issue. Bleach fumes don't take a long time to settle, the smell evaporates quickly and the poison itself breaks down to give salt water. Obviously, the spray has no lasting effect. You have to hit directly to the target. I have found this very useful when getting rid of wasps in the attic. They're angry and dangerous, so the objective is to kill them instantly before they have time to react.
(1 Sodium hypochlorite bleach
is an irritant
, i.e. it does not destroy tissue and cause burns in humans, but it is damaging and lethal to insects, that is, a poison