Although equipment and procedures exist to clean out the large DPF devices that work on heavy trucks, construction machinery, and large marine engines, there are no reliable ways to clean out the smaller DPF devices that work on light vehicles.
The main reason for this is that the passages in the cores of small DPF devices are too small to allow the chemicals that can remove carbon and accumulated soot in heavy-duty DPFs, to be forced through the core. Sadly, this fact does not seem to deter some service providers from claiming that they can flush out any DPF on almost any light vehicle to restore its functionality to the same level as when it was new.
Put simply, there are no known ways to restore the functionality of a severely restricted DPF on a light vehicle by forcing chemicals with unknown or dubious qualities through it, or by blowing a mixture of oxygen and propane gas through it, and then igniting the mixture to "burn off" the soot. The most likely outcome of these two "repair methods" is either a completely blocked core, or a melted core, both of which render the DPF useless.
However, one possible way of repairing a severely clogged DPF is to have a professional workshop perform a forced regeneration of the DPF with a suitable scan tool. Essentially, the scan tool will make the engine control unit believe that all required enabling conditions have been met, meaning that the engine control module will attempt regeneration of the DPF while the vehicle is stationary.
Unfortunately, though, unsuccessful forced regenerations greatly outnumber successful regenerations so, in a practical sense, the only reliable remedy for most DPF issues is the replacement of the defective or clogged DPF with a new OEM or OEM-equivalent part by a competent workshop.