I bought this pest killing chalk from reliance super mart and they display their ad by a cockroach, and they said it should wipe out all pest from your house and I bought that and line this chalk on each affected area on my flat and wait for the result in 2 days. No changes happened. And I just saw some funny scene at my kitchen too, a cockroach is eating some rice waste that falls on the this chalk : ) ! And he goes like he done a thug life . So I suggest some other chalk to kill pests from your houses, am still finding a good one.
