Permanent solution for cockroach problem
Stop using over the counter products.  They don't really work.  There are some sure fire ways to get rid of roaches inside.  Of course this is only for moderate infestations.  If you have small children you may not be able to take the approach I recommend.  Read all warnings on pest control products, especially if you have birds or small pets.  The suggestions I make below come from my experience researching and dealing with a moderate roach problem (and huge ant problem) I inherited after I bought a house in Florida, which had been vacant for a couple of years.  


Clean up everything.  Remove clutter, vacuum up any debris. Clutter is a roach's best friend. Use a mild cleaner to clean up anywhere they've been.  If you can vacuum up the roaches themselves, that's great.  
Put a barrier around entry points.  A barrier is a poison that insects pick up when they walk through it, and eventually die.  Dust outside window ledges with a product like 
Delta dust. You will need a duster (Use tip: you have to shake the whole container  before you pump it). Spray a barrier spray along the outside of the house on the ground if you want.  Bonus: the dust works even better on flying insects, like wasps. 
See if you can find the nests.  Common hiding places are in, behind, and under fridges, dishwashers, stoves, and electrical boxes.  They like nesting in loose paper, behind some wallpapers, etc.  If you can find the nests.  Hit them with the powder.  Use some powder under appliances even if you don't think there's a nest.  
Bait the roaches.  Powders and barrier sprays are good, but most killing will be done with the bait.  I pretend I'm a mad/evil insect villain when I place it.  Baits allow the roaches to bring the poison back to the nest. I have used Dupont Advion and MaxForce(Fipronil) with success.  Put small droplets of the bait in corners and along baseboards.  Anywhere the roaches may travel, including counter-tops.  Put the bait on small pieces of paper to avoid staining.  Don't powder or spray where you've baited. If you have kids, you'll want to use a bait trap as a minimum precaution.   


If you do the above, the roaches will be all but gone in a couple of weeks.  That is unless there are extreme circumstances, like a hoarder in an adjoining townhome.