The first step in succesful eradication is to find the source of water. Invariable there is a leak somewhere that is providing water for them.
Until that problem is addressed, you will never get rid of them. Once it is addressed, any of the typical pesticides or baits will kill off the Colony, but if you don't address the water issue, you will just get colonized by roaches again.
If you cannot use pesticides, if you can cut off the water supply, the use of adhesive baits (non toxic) will evenutally take them out of circulation.
They step onto the adhesive, and promptly get stuck permanently. A package of 6 is about $2 at Walmart. They smell like peanut butter to attract, but have no toxic chemicals.
If you see them, and have fish or birds, you can use a mist sprayer used for plants filled with rubbing alcohol instead. Getting the roach wet will produce a lethal concentration of Isopropyl Alcohol for the Roach, and kill in about 30 seconds, while the fumes will remain far below toxic levels for pets.
Pick your treatment carefully if you have pets.
Birds and fish are especially sensitive to most sprays. If you have to spray, get birds and fish out of the house, and keep them out for at least 24 hours. If you use liquids that you apply, make sure they are applied only in places your pets cannot get too.
If you bait, make sure the bait is in places your pets cannot get to.