Thing is, I'd like these tools to wearing muzzle to lose weight. It's misdirection of effort into avoiding rather than addressing the demonstrated issue of self-control.
No one has infinite willpower. Making it a tad harder to browse reddit is a useful deterrent. It makes you think twice. If you're trying to lose weight, wearing a muzzle is extreme. However, it's a good idea to remove all the junk food from your house. You can always buy more, but it's that much harder.
If you habitually procrastinate by browsing to reddit et al, these tools can help by killing the positive feedback (as the sites appear down). After a while you no longer have the urge to visit the sites, and the tool isn't necessary.