Agree with everything said here.^Personally I think that these kinds of measures will always prove ineffective if the mindset is not correct.
You can set up all kinds of filters, and means to try to stop yourself from looking at pornography, but you will fail unless you can alter the mindset that makes you want to do it in the first place.
Let's say you are addicted to crack. Having filters on your internet or otherwise trying to impose limitations on your pornography, is like having a safe with a load of crack in it, that you can put in a box with a padlock inside a safe with a combination, but as long as you want to smoke crack, you know the combo, you have the key to the padlock, you can get to it if you want it. You will inevitably fail if you do not conquer the mindset that makes you want to smoke crack.
You can have 15 different steps to take to get to your crack, but it is all for nought if you do not conquer your desire for crack. Otherwise you'll just bypass however many steps you put in your way, and you'll get to your crack supply.
It is imperative that you realise that you are a hopeless addict, that the drug does nothing, absolutely nothing whatsoever for you, and that your life will be better without being enslaved to it. Otherwise you'll just be trying to trick yourself by putting your beloved crack in a safe that you know the combo to, inside a box that you have the key to. It's just not going to do anything if you still want your crack.
Making things 'more difficult' doesn't address what is causing one to gravitate towards the problem.
The above being said, there's nothing wrong with taking steps to assist yourself along the way. For example: Do you have pornographic images saved to your computer? - Delete all of them. 'Subscribed' to a place you shouldn't be? - Unsubscribe. 'Bookmarks' to questionable material? - Clear them all out. Have hardware-media in your home (Videhos. Playsoy magazine, etc)? - Gather them all up and DISPOSE of them. Not 'Re-sell'; LAND-FILL/DESTROY. (Compare Acts 19:19)
And, for families, always have the computer of the home in the common area where everyone can see it - do this regardless if anyone has had problems or not. (Also, no personal devices with Internet capabilities for any minor children - I'm sure this appears debatable/extreme, I know, but that is how I would run my household).