I do, then I have no trouble remembering when I last changed them.
The firefighter is right, also just heating it makes it wetter. Spill something ice cold on your jeans and you can usually wipe it off before it soaks in, a hot cup of coffee or tea on the other hand sinks in instantly.
Do you mean will the smoke detector activate a fan instead of, or in addition to, a buzzer? I would recommend connecting the fan to the buzzer terminal using a transistor, so as not to add a significant current draw to the circuit. You may pull the voltage down too low for the circuit to work properly.
