I've always heard of that referred to as a "bush tune".
High engine revs mean higher heat and higher flows and in a petrol car that might shift a bit of muck from the pistons, but the intake manifold is normally quite clean because it's usually a vacuum - the cylinders actively draw everything in.
In a turbo diesel the intake manifold is under positive pressure nearly all the time. This doesn't mean it's going to push the gunk into the combustion chamber when it opens (it will, but not ALL of it) - it does mean that it can deposit the gunk anywhere in the manifold at all (because pressure works equally in all directions).
There are a couple of things you CAN do.
1) Block the EGR. EGR contains soot, soot combines with PCV oil vapour and forms a black sticky goo that doesn't move. Blocking the EGR removes the soot from the equation completely.
2) Fit a catch can. This removes most of the oil vapour from the intake path. There'll still be a small amount, but nothing like what you had before.
3) Clean the intercooler. No, not the outside of it. Pop it out, grab some pure unleaded (not 2-stroke, not metho, not xylene etc - it MUST be unleaded petrol). Block one side of the intercooler with your hand, pour in about 100ml of petrol and block the other side and turn it over and over letting the fuel flow through as much of the paths as possible. Repeat a few times until you can see the petrol colour coming out. Empty it, let it sit to dry for an hour, then reinstall.
You could also use Liqui Moly Diesel Purge (extreme) or Liqui Moly Fuel System Cleaner (easy, just $25 at SCA, pour into the fuel tank and drive it). These will clean the fuel paths, including SCV (vital), injectors (yep) and the rail.