Cockroaches are very difficult to eliminate, and attempting to take this task on your own can make the situation worse.
In the case of German cockroaches, the use of repellent insecticides such as pyrethrins and pyrethroids is ineffective and may become more costly in the long run. These sprays only kill a few roaches that are directly exposed to the toxins, but the ones that survive will scatter away and infest other rooms in the home. After a while, you may find yourself dealing with multiple infestations inside your home rather than having them localized to the kitchen area. Foggers are made up of pyrethrins, so they are also ineffective.
In the case of palmetto roaches, unless you are able to get the insecticide inside the walls, in the attic, or in the crawlspace, you will not be able to stop them. Homeowners typically do not have the tools and knowledge necessary to adequately apply the products in these key areas. Be careful when hiring cheap pest control companies; if all they do is spray the baseboards, you are wasting your money. It doesn't work!