Here is a detailed how-to on DIY diesel injector cleaning using Liqui Moly's Diesel Purge Plus injector treatment on a 2011 VW Polo TDI. I detail all of the required parts and tips and tricks on how to compete the injector cleaning.
I found the TDI ran quieter after the treatment and felt more spritely and smooth. For $20 all up, it was worth a try as the injection system on these modern cars is upwards of $2000 - good to look after them and try to keep them clean.
Let me know if you need any help - I'm happy to.
