They are the things a homeowner's nightmares are made of. They are, in many people's opinion, the very definition of a creature that serves no good purpose. They are roaches, and chances are you've come across them in your time. A good stomp will take one out. So will a good spray of Raid. But what if you want to get rid of a bunch of them?
Before setting off on a killing spree, you have to determine whether or not your problem is, in fact, roaches. You'll recognize the roach by its slender midsection and its long antennae. It resembles almost no other insect on the planet, except possibly the beetle. The beetle, however, has a much thicker shell casing, and is typically darker in color. If you have seen a single roach, chances are there are more where that came from. Killing them one at a time is a fool's game. You have to go to the source.
The next step in taking care of your roach problem is to discover the location of the roaches' home. No, this doesn't mean you have to locate the roaches sitting back, lounging on the couch, and snacking on a bit of crust you left on the floor two days ago. It simply means looking around the house for possible places where roaches could be entering the home. This means cracks and holes that could lead outside. Vents and drains are other likely places. If you have a basement or an attic, check there first.
After identifying the problem, it's time to find a solution. Of course, the easiest way to go about this is simply to buy cockroach spray at your local grocery store. This spray does not have to be applied directly to the roach to be effective. Take the formula and spray it around the areas where the cockroaches are coming from for an efficient method of killing your roach family.
Another option is to buy some cockroach bait. This bait masquerades as food for the roaches. A scout roach will take the bait and bring it back to the colony. The bait, of course, is poison. The scout roach has effectively killed his superiors by bringing this nasty bit of business back to the home. Sad stuff if you're a roach, but good news if you're a homeowner.
A boric acid solution is gaining some measure of popularity in the field of roach removal. Mix the boric acid with flour and cocoa and you have a treat that will both attract and annihilate any roaches in the area. Like the pre-made bait above, roaches will bring this back to their lair and share it with the whole crew. It is the perfect Trojan Horse to wage war on the roaches in your home.
Some more of the most popular roach killers come in the form of traps. These traps are developed with a special aroma that attracts roaches to the scene. They are then trapped inside by way of a strong glue. You simply check the trap, note the dead roaches within, and toss it out. These are sometimes called roach motels.
Through the Internet, professional pesticides are now available to the general public. Get some of this stuff (look for a product that has the ingredient "cypermerthrin") and spray it around the outside edges of your home. This will almost certainly take care of your roach infestation. As a precaution, read carefully any and all warnings that come with such products. Also, a caveat: these products will kill not only roaches, but any other forms of insects or spiders that live around your home. Likely, you'll see this as a good thing, but something you should be aware of nonetheless.
The answer to the question outlined in the title, however, comes down to something much simpler than all the other solutions. Many experts in the pest control field recommend that the best product to kill roaches is a mixture of things you already have in your house. It is a simple concoction consisting of nothing more than soap and water. Mix this and put it in a spray bottle, and you have a homemade bug spray every bit as effective as the stuff you buy in the stores. Bath soap will work fine. The roaches won't know the difference once it hits them. Roaches have a unique breathing method. They intake most of their oxygen directly through their skin, rather through a set of lungs, as humans. Therefore, anything that can clog and suffocate this breathing method will surely kill them. Cockroaches as a species may outlive nuclear war, but they won't outlive a good bath.