I used it with fantastic results. I used a cheap garden sprayer and put the separate chemicals (following the instructions) in via the dpf pressure sensor hose.
Be warned: when you get done you might find other issues pop up. I had a bad downstream O2 sensor - I removed it, put it in some cheap fuel injector cleaner and strapped the bowl to an orbital sander for several hours, reinstalled the sensor and it worked great. Next issue was the NOX cat wouldn't regen - I removed it, cleaned it with a foaming carpet cleaner from walmart, water from the garden hose, and shop air to blow it all out. I foamed it up, rinsed it out, and blew air through it several times until I could finally see some light coming through from the other end. Installed it on the car and it regen'd without issue.
I had some upstream issues that had to be resolved prior to all of this - generally speaking, if something is wrong with the intake, fuel, or exhaust, the computer will not allow a regen. So check codes and make repairs or the computer will never let you regen the DPF or NOX cat...I've since done 10k+ miles - 2012 JSW TDI w/DSG, paid $2500 for a salvage title. Around $2k later for various body panels and parts and we've got a handy daily wagon with a rebuilt title.
