05/28/2026
Researchers tested this in real apartments, not a lab box. The result was close to zero.
A 2016 study out of North Carolina State and partners put commercial total release foggers up against German cockroach populations in infested homes. They measured roach numbers before and after, and they placed sensors and monitors in the spots roaches actually live: inside cabinet voids, behind appliances, in wall cracks. The fogger residue barely got there. Population reductions in the hidden harborages were barely noticeable.
The reason is physics. Fogger droplets are tiny but they still fall and land on horizontal surfaces. They don't get pushed into a 1-millimeter crack against gravity, and German cockroaches spend almost their entire lives in exactly those cracks, coming out mainly at night to feed.
The same study ran gel bait as a comparison. Bait cut the populations dramatically, because roaches go to the bait, eat it, and their cannibalistic behavior spread the toxin like a diseas.
So a fogger gives you a fast pile of dead roaches on the floor and a colony in the walls that didn't even get touched. Worse survivors that are scattered repopulate wherever they end up.
There are two options here. You can do it yourself or hire a professional.