I think the math problem could help, but you also need to ask yourself if you're just going to keep bypassing it anyway.. in which case software is unlikely to help much.

For you I would recommend the book: The Willpower Instinct by Kelly McGonigal. (audiobook is also well narrated)

It's well written and full of great methods for gaining your self control back.

I myself have tried these types of apps before which sometimes might help, but often I face the same problem as you, when my behaviour devolves to disabling the add-on and doing whatever I want.

Now what I have practised is being mindful of my actions, and treat the time when I work, study as time without youtube videos, without writing long HN posts and so on.

It's a lot harder than having some app to ping you to stop browsing. But I think it's what works better in the long run. You choose the time when you work, say a couple of hours, then take a break. No mindless browsing in between. Or well actually what has worked best for me is to have no mindless browsing at all during the best part of the day, since the feedback loop is too strong when you get accustomed to looking "just one more video".

But I'm curious to try this out. We'll see. But I'm sceptical.

I, too, had that problem, but pins and random math problems aren't so good. What works for me is taking a random piece of text, converting it into binary and using that as the challenge text (to retype). Typing so many 0s and 1s would require a lot of focus - I'd never dare even try changing the configs.

How about having to hold the button for 5+ seconds before it activates?

Yep, same problem here