I had my Triton at the stealers today getting some problems fixed , whilst I was there I commented on the carbon build up and was told that "there is a new intake cleaner they have just got hold off and which will clean the carbon out of the intake manifold, it is similar to the Subaru but haven't worked out a price yet."
They heard it does a "pretty good job", and also "some people are putting in a egr blanking plate" to stop this from happening.
Never argue with an idiot, they'll bring you down to their level and beat you with experience