If you're going to spray an entire room, then keep cabinets and drawers open for efficiency. So remove all food, eating utensils, and pets before spraying. If you choose this route, you must absolutely consult a professional exterminator. Products such as Combat and Raid MAX can be placed in the kitchen, bathroom, and other infested areas. Baits are nice because they attract roaches, trick them to taking poison into the walls to the other roaches, and then it kills them all at once.
Baits are usually effective for three to twelve months.
Boric acid is applied as a dust in wall voids, paths along which the roaches travel, and other hangouts. It's organic, generally safe, and should be used if the rest of your home has already been thoroughly treated for maximum effectiveness. A benefit of boric acid is that cockroaches will transfer dust from roach to roach, reducing a hidden roach metropolis into a ghost town. If you want to know the grizzly details, boric acid eats through cockroach shells gradually, taking anywhere from a few hours to a few days to kill the suckers. If there's nothing to eat in your home, most roaches will just go away.