Thank you for your replies, I had no idea that this was a dodgy thing to do!
I would never want to take any risk where insurance and MOT are concerned, so I will definitly not be going down that route.
Since my last post I had managed to clear the DPF by taking the car for a run down the motoraway, But.......
Unfortunatly the car went into restricted mode when I let the diesel run down to 25 miles range, looking on the internet it said that fueI being low could have been the problem. I filled up and the problem went away for about a week.
It has now gone into