Actually I've found that by setting up a blocker on my devices that I can toggle on and off at will is enough.

When I start the workday, I toggle it on, and every time I try to load my social stuff (HN included) it puts up a big red warning.

I found that the majority of my wasted time was because I impulsively opened a tab to somewhere during like 10 seconds of downtime while waiting for something. And having this little block in place stopped it in its tracks.