Making Nedarim (vows) can be a very powerful tool in this struggle, and Chazal indeed encourage Nedarim for these type of tests. However, vows must be made very carefully and only for short periods of time (at first) to assure that they can be kept under all circumstances. See this page and this page of our site for advice on how to make vows safely and effectively to help in this struggle.
I had a fall recently, and afterwards I gave some thought to my general direction. I realized that although I feel that I've pretty much broken the HABIT, I need a stronger commitment to keep myself strong when I get that rare POWERFUL urge that seems irresistible. So right then, I made a neder (which I knew I could keep) not to allow ANY lust for 2 weeks. That means visiting any site with any lustful intent, or even allowing any lustful thoughts to remain in my mind at any time. (I vowed that if I allow any lustful thoughts to linger, I will do 30 push ups). It really seems to be helping! On only a couple of occasions unwelcome thoughts have come to me, but because I made a neder, they cannot stay, and just like on a fast day I have no problem fasting and my stomach doesn't growl like it would on a regular morning because it "knows" it can't eat, my mind lets go of the thoughts immediately because it "knows" it can't "eat". Soon the two weeks are up and I will renew the vow for another 2 weeks, and I figure I'll keep doing that to keep totally clean. The summer is a VERY difficult time, and overall I think it was a success, with only 2 bumps in the road. I was able to prevent myself from falling back into a rut, even when it seemed like that was where I was headed. November will be a year since I started this journey, and I'll be sure to keep you up to date on how I'm doing. What you always say is so true: "The less you feed it, the less you need it".
Today, I tried out a small neder (first time). I was alone in a house (b"H someone took the laptop so I didn't have internet) but there were plenty of non-Jewish magazines. The length of my neder was just for the afternoon; that I would do 25 push-ups before opening any non-Jewish material. After the fact, I think it helped keep the pestering voices out of my head pretty well!