They don't kill roaches, but they do cover everything in your house with a film of poison. In a study, bug bombs did nothing useful, at least when it comes to roaches.
Scientists set off four kinds of bombs and placed two kinds of baits in 30 infested homes in Raleigh. Twenty homes got one of the four bombs and 10 got one of the two baits. The scientists counted the number of cockroaches before treatment and after, once at 2 weeks and once 1 month later. In every home that had been bombed, cockroach numbers stayed the same, the researchers report this week in BMC Public Health. With one bait, populations dropped by more than half after 2 weeks; with the other, they plummeted by more than 75%. Numbers went down even more after the full month.
Here's what worked, according to the study published in BMC Public Health.
Only the two bait treatments resulted in significant declines in trap counts relative to baseline (Combat: F2,8 = 12.40, p = 0.0035; Maxforce: F2,8 = 21.37, p = 0.0006) at both two- and four-weeks after the intervention
Amazon has them both, as luck would have it. Combat Roach Killer Gel is cheap and comes in straightforward single-use packs. Maxforce is a pro-grade gel bait that comes in tubes or bait stations