hmm.. well, if you are trying to do that, im pretty sure your addiction will cause you to reinstate that link, and unlbock it. so in terms, your probably not gonna stop visiting it anyway.
the best way i can think of right now, is if you have a computer geek friend/family, have them do it while your not there, and hopefully, you will not be able to change or modify it.
an example is zonealarm. it has the password safeguard option. have a friend do it, set the links up. then have it password locked so only HE, not you, can change the setting for the link.