I was fueling up today next to a older chevy diesel (junk). And the guy was putting chimney sweep in his tank. I asked what in the world are you doing? And his answer was that it makes awesome smoke and cackles when you get after it. I left it at that. I figured that this guy is nuts already. What is your guys take on this? I guess it is possible but wouldn't that coke the injector tips due to burning to hot? Has anybody tried this? I do not think I will be the Ginnie pig on it.