What is the best cockroach killer?

According to Landlordology, boric acid is the best roach killer. The substance is inexpensive and is available at most grocery and hardware stores. Landlordology states that boric acid takes one to five days to start working.

Boric acid is available in powder and tablet form, and should be placed in areas of the home where roaches are seen most often. This may include moist dark parts of the house. Other effective roach killers include Harris Roach Killer Powder. Landlordology states that Harris works faster than other roach killer brands. Mixing the powder with condensed milk can attract the roaches to the solution quicker.