The best way is to unbolt your EGR pipe at the intake flap, with the engine off, and pump that area full. Try and get the hose up in towards the manifold / four inlet ports. Bolt the EGR pipe back up and let it sit for a good while, and then try and start the car, which will take a bit of cranking. It will struggle and run rough till it clears. The next step is to spray it in with the engine running, I do it on idle and just stop as it labours, but I put it in PRE TURBO where the PCV inlet just before the turbo is in the air intake. The idea of a big pool in the intercooler is false, for sure you end up with some, but the whole idea is to get rid of buildup. Your intercooler ends up with a nice layer or engine oil from the turbo bearings anyway, don't kid yourself it stays nice and clean, better to try and flush it out a bit with these sorts of sprays. For sure they don't beat a physical clean, but who really bothers in the general public, as it's a super dirty job. These sprays sure beat doing nothing!

Put it in anywhere AFTER the MAF and you will get some effect, diesels are alot tougher than people think. The REAL issue is all this crap ends up in your DPF, whether cleaned out via spray or not, I think you should all worry more about that!