Hey bud, dust takes years to accumulate. I think the best thing you can do is just keep the immediate surface in which you put your laptop clean at all times. So as long as their is no dust on your work surface you are greatly minimizing the amount of dust accumulating on your fans. Also the amount of dust that will accumulate over years only minimally affects your CPU/GPU temperatures. So I dont think you will see any difference by cleaning it every 2 months.