I haven't. I've quit addictions before. But it has come to pornography being the last of my known big sins. And it's the hardest one to break of all. It's like the evil within me knows its on its last legs, and is therefore using pornography to hold on to its dear life harder than ever before. The evil's primary weapons are using the fear of my life becoming boring, and incapable of feeling intimacy for the opposite sex, without phonography. To quiet the evil, I meditate on scripture with applications to fantasy and escapism, such as "Better is the sight of the eyes than the wandering of the desire: this is also vanity and vexation of spirit." I have also greatly reduced ownership over material possessions which no longer bring me joy as a way to show myself that life still goes on even if I am "without" and "bored."
At the end of the day, however, my efforts can only quiet, but not quit, the evil. It's as if this suffering is one thing God is keeping the keys to as I means to exercise my unconditional trust in him. After all, the race goes to people according to time and chance, and not by man's efforts. And the man who put away childish things, was already a man before putting away childish things. It is not the putting away of childish things that made the man.