Has anyone tried Lubro Moly Diesel Purge straight without pouring it in your tank? The instructions say for best results run it straight. My question is: How do you do that? I know there is a fuel return line that would have to be rerouted back into the can of Diesel Purge, but I'm not sure where it is. Has anybody done this?

Guess you could fill your fuel filter with it. I've heard of people doing that with Sea Foam.

Yes, but the excess that is not burned will return to the fuel tank, thereby diluting it. I have seen youtube videos of Volkswagon TDI people running it straight from the can including having the fuel return rerouted back into the can. I was wondering if that can be done with Duramax.