In my other page, I covered the natural roach killer, diatomaceous earth. I covered it in depth, but that was all it covered. To really stand a chance at getting rid of them, I feel you need to at know more than one method. Although you may not need to use more than one method for the desired results, a combination of multiple methods may increase your chances of success and reduce the time it takes to achieve the results. Since our aim is to stay as close to baths solutions as possible, I won't be discussing the synthetic pesticides like Cypermethrin and such. I'll be concentrating on alternative methods that are still natural.
Boric acid is probably the most popular method out of both natural and synthetic pesticides. It's used by both professionals and home users. Think of boric acid as Diatomaceous earth on steroids. It's definitely not the same thing, but it does produce almost the same results in the same manner.
The powder being abrasive cuts into the exoskeleton and causes dehydration. What makes it completely different though is what happens when a cockroach eats it. The boric acid, once ingested, will attack the stomach of the cockroach that ate it and severely affect it from both the inside and the outside.
Use is basically the same as Diatomaceous earth. You lightly dust it in appropriate locations. One other difference with boric acid is you can mix it with an attractant like sugar and make your own homemade cockroach bait. It works just as well as the commercially available roach bait products out of the market.
To make roach bait out of boric acid, just mix 2 part boric acid and one part sugar. Mix in a small amount of water until you get the right consistency. You can add a little flour to the mix to make a dough or pill roach bait. Or you can get a thing paste similar to the gel baits you can buy from the store.
Borax is often mistaken to be the same as boric acid. Although they are very similar, they are still different. Perhaps they are often mistaken for each other because they do the same thing and are used the same exact way. In fact you can just use one or the other. You can make bait just like with boric acid. All you have to do is substitute boric acid with borax.
One big difference between these two is where you will find them at your local store. Borax is most commonly found in the laundry detergent Isle, sold as a laundry booster. While boric acid is found in on the pesticides aisle along with all the nasty manmade bug killers.
Soap water mixture
Ok so you can probably argue this one dating that the detergent used in this method is manmade. But it's a very harmless method (to you and your kids) so I decided to add it here.
Cockroaches breathe through their exoskeleton through tiny microscopic breathing tube (kind of). When you spray them with a soap water mixture, it covers them in in a thin film of soap that stops them from being able to breathe. Without air, they eventually suffocate to death.
To make this, all you need is an empty spray bottle, dish detergent and warm water. Just mix the detergent and water in the sprayer until you get a nice soapy mixture that's easy to spray. Spray the roaches as you spot them and watch them die.