Excellent to hear more thinking on this topic of getting the fridge to light
and stay lit. 

I think possibly the following:

The combustion chamber automatically empties itself of bad air due to the
draft created by the hot air from the flame so when the thing is lit there
shouldn't be a problem getting rid of the stale air. 

The problem is when it is not yet lit. The device you describe would be hard
to use because you would have to keep driving while trying to get the thing
lit for your device to work.

And if it *was* already lit, your device might create a draft and blow the
flame out.