creating the damned glow!

A problem i have been having has been getting the toaster to "glow" as mentioned in the footage...
Had i known it was hard i would have said it was doing something else unusual.
It would technically be easy for me to simply re record myself saying something else, as im behind the camera there would be no dubbing issues etc.
But im a glutton for punishment so i will keep at it. here is one of my terrible attempts.

I want the effect to appear as a light, not just a flashing section. so the light needs to orginate at the bottom and glow...