I have same stove too. I have used up many tanks of gasoline, the soot accumulation was not that much. I wonder if there is a carbon deposit when running it with Coleman Fuel. In my 400A generator clogging case, I have seen small brown color particles and solder droplets (I have soldered a nut to a screw,) in the alcohol I have sucked for rinsing the generator. Brown particles are rust. I have not seen any soot in the tip cleaner part. For instance I have noticed that the stove starts running with blue flames when the tank is 1/3 full approx. When I open the fuel valve, a hiss sound comes for 2-3 seconds without any flames, then blue flames appear.