i think it is a good thing as i cleaned my throttle body a few months back and i can tell you it was dirty very dirty
looking inside the inlet manifold also the same conclusion recycled oil and
carbon build up
also on the EGR pipe and the EGR valve and
carbon build up on the boost sensor
i also believe the swirl flaps and inlet pipes get very clogged also
not the best option to remove the inlet manifold to clean them out
also the turbo and internals will get a good clean along along with the DPF filter
if this type of cleaning is done
i was looking at this
https://www.youtube.com/watch?v=pAJSOsIbqyc
the only issue i see is if you get an engine managment light after doing that the car may need to be reset
but it looks beneficial to me if it can get to the places that are hard to get too manualy.
i do run DPF cleaners and injector cleaners through the tank every few months
and i only use shell v max or other premium fuels to help also.