A professional DPF clean by a reputable company can be highly effective, restoring it to the point where it is not quite as new but significantly better than before to the point where it can operate correctly and should remove the engine fault. However it is also important to look at the cause of the blockage in the first place - frequent short journeys and a lack of longer runs will mean the DPF does not have sufficient opportunity to regenerate, so if this is the case then it will only be a matter of time before the problem returns. It is also worth looking at other potential causes, such as a lack of DPF fluid or failing temperature sensors which prevent the car from performing a regeneration as it should.