A filter is not recovery. It doesn't even come close to anything like recovery. If anyone who really has a chronic problem "works on their problem" just by putting on a filter, they are kidding themselves.
In that way, putting on a filter will actually perpetuate their problem and mess up their recovery completely - they will think that putting on a filter is all the real action they need to take.
"Phew! I had an alligator in my basement that would sneak up at night and bite my leg. Then someone gave me a great idea and I finally shut the basement door! Finally I can sleep at night."
This alligator-fellow is a weirdo. Who wants an freaking alligator in their basement?! Eventually it will chew through the door, and everybody knows that. Gotta get it outta there.
A filter is only as strong as my acceptance that I cannot afford to test it. Once I test it, I might as well not have it at all. My alligator will eventually get through, guaranteed.
So I say, get any decent filter (I like K-9), and throw away the key, give it to your mother, wife, brother, anybody. Then realize that the filter is just a reminder, nothing more. Evidence to myself that I do not want to screw up my life with crazy obsession with porn and sex with myself, any more. Nor with the struggle against it - which is just as poisonous.
Recovery is my main work now - not learning, not my marriage, not my davening or anything else - just recovery. For it is obvious to any ba'al seichel that if an addict does not get deep into real recovery and take real steps and do real recovery work, he will not have any of those important parts of life anyhow!
In other words, either I will learn how to use a relationship with G-d to save me, or I am finished.