Shree Agni Rekha Chalk household insecticide chalk. For a cockroach free home, draw 2-3 thick parallel lines around Dustbins, Lifts Cabin, and Drain Holes, etc. which are frequently visited by cockroaches, preferably during Night-Time. The effect is clearly visible in 2-3 hours. On glazed or smooth surfaces like Tiles, Wet the tip of the Chalk to draw lines.