(I don't have a disorder, but) for me the case is often that I just mindlessly click my HN bookmark, open reddit app, lichess puzzle etc to kill a few minutes. Just the popup telling me that it's blocked is enough to make my brain realize what I'm about to do and abort. I could just click the button to override, but my "mindlessly browsing" mode got disturbed and suddenly I'm conscious about it happening.
For a few decades I tried and failed to make hostfile blocks, guided access mode, browser focus-tracking extensions, day planners, public accountability, timers, and more work for me.
What actually works as I count the weeks to my fortieth birthday is a fragile and ever-shifting combination of adderall, sleep, diet, exercise, therapy, e-ink devices, and the courage to be open up and be vulnerable with those who depend on me at work and at home.
Splurging on a color laser printer and an e-ink tablet have given me two more ways to have a hope of staying on task a bit more every day.