I'm going to tell you my experience of Wynns DPF cleaner.
Please don't take this as advice, I'm not qualified to give you advice, it's just my experience.
A relative drove 180 miles to stay with us, in a Nissan Qashqai 1.5dci. The journey was mostly motorway at 70MPH.
When she was nearly here it went into limp mode and EML light illuminated.
I had a look and it had blown a plastic hose connector on the intercooler, which I replaced. (A blocked DPF had probably caused the excess pressure which broke the pipe).
I reset the car out of limp mode but a blocked DPF light came on and every time we went over 2,000 revs the car went into limp mode with a DPF light illuminated.
I chucked two little bottles of Wynns DPF cleaner into a full tank of fuel and drove gently for 10 miles so it didn't go into limp mode, then drove it hard, on the red line mostly, for ten miles.
That was 500 miles ago, it's been fine since then and hasn't been near a garage.
I'm certainly not suggesting that it would "fix" your problem, the Nissan was a Euro 5, so no AdBlue, but in your shoes I personally would try it on the basis that you've only got £12 to lose.
