I also do a lot of tapping up the back wall of the burn chamber and esp. in the corners. I use the handle of a a plastic screw driver, gentle but enough to cause white flaking ash to fall. Stove performance is always improved with this cleaning. I also liked that video. I think most stove owners can gain some confidence and insight into stove cleaning when they watch it.I will be honest but until watching the video that save$ posted I never knew about the little plates in both corners that you can remove and clean located in the fire compartment (I think they're called "exhaust port door" ?)
I just did some cleaning to my unit and man there was a lot of ash accumulated in there..!!
Thanks save$...