zlacker

One thing I haven't seen mentioned yet is LeechBlock for Firefox. With it, you can set up site block lists that will either never allow access or allow access after a period of time (60 seconds default) and on a schedule.

I have found this helps because when the motivation is that dopamine hit, the delayed start generally gives me enough time to think, "I should be doing something better with my time."

Edit: of course you can reconfigure and delete LeechBlock, but if you are committed to reduced scrolling it helps. (Obviously I haven't been able to do it with hackernews yet.)