15 years ago, we had neighbors move in. Shortly after, they had roaches (so bad that they were on the outside of the house at night) and of course, they rover, rover, came on over. I can't remember exactly what we did, but I do know you have to keep at it because the bombs don't kill the eggs. You should probably pull all appliances out and scrub down everything. Even if you keep clean, there could be food particles down in the crevices that you don't know about. Even grease is yummy to them. Once you have everything sterile, keep bombing and raiding. Eventually, you'll kill them off and will have left them no option for staying.