Rick from New York writes
If I remove an unused electrical switch from the wall and place a Gentrol disc inside, and then cover the hole back up, will that work to control roaches living behind the drywall?
The Gentrol Point Source is designed to work in areas such as open rooms, closets, or cabinets, where the active ingredient vapor can move throughout the space. We would not recommend trying to use the Gentrol Point Source inside a wall void. You could apply an insecticide dust such as CimeXa Insecticide Dust into wall voids for long-lasting control of roaches in this area. Please see our Roach Treatment Guide for more information about treating for this pest.
Answer last updated on: 01/31/2016