The exterminators may not have been professionals. If they would have used the right chemicals there would be no bed bugs in your rooms for a year. A good company that knows the job also gives you a surety of this. The technique advised by techn is good. I would just like to add something. After pouring boiling water at all places on the bed especially around the corners and cracks or joints, you could follow it with by mixing a high concentration of Dettol with water and pour that again. You will need to place the mattress, pillows, comforters etc out in the sun if possible and make sure there are no bugs or their eggs in them Otherwise the entire effort would be futile.