I made MooBlock - a browser extension for digital self-regulation. Basically, it adds a small timeout before you can access a distracting site. This timeout grows the more you visit these sites, and decays when you stay away.
And yes, there are lots of cows. The longer you stay on distracting sites, the more cows appear.
The idea is to make distracting sites less appealing, without using a black-and-white site blocker, which you can easily disable.