Depends what you mean by dpf cleaner.We use a 2 part cleaner,basically acid based solution direct into front end of dpf,pump it through and let it dissolve soot,wash through with part 2.put all back together and run car on a forced dpf regeneration,road test,all good.About an hour labour,£100 parts,£50 diagnostic.
After this treatment it should be good for another 100k miles,but ask yourself why it's blocked?do you have a pipe blocked,a dpf temp sensor inop,or something else.
If you mean dpf cleaners that you add to the fuel tank,you're wasting your money.Most cars will regen of their own accord about every 150 miles,regardless of if you do short journeys or long journeys,but if you only do short journeys it won't be driven for long enough to complete regen,if that makes sense.
I will say,once your dpf is blocked the car won't unblock it on its own.Hope this helps,far to many different varieties of car to give an exact answer,but hopefully you get the idea,cheers.