I have been reading a few posts that suggest burning wide open for about 1 hour, once a day, to clean out any accumulation. I understand the reasoning behind this advice. I am assuming this is how it is done: On the BK, I need to turn the t'stat all the way up...to the 3.5 setting Turn on the stove fan to keep the stove from getting too hot. Here is where I am not sure: Should I do this hot burn with the cat engaged or no? Is an hour necessary, or will 1/2 hour suffice?