Reject Convenience Forum

The most recent Reject Convenience video convinced me of the importance of regular cookie deletion. My tolerance window is different and I'd like to go for a medium option, where I delete cookies every... month, let's say. I think that would be a good compromise between "every time I close the browser, making all my preferences in websites constantly vanish" and "any time I remember to delete them because something bad happened, which is rare."

Jumping to the point: the video says "most browsers offer options on when to clear them automatically," but I've been unable to find this on both Brave (Chromium) and Firefox. Both offer an option where it deletes cookies upon browser-closing, but I'm not seeing anything about regular intervals e.g. monthly. So I'm asking for some help/advice on this. If this isn't possible natively, an extension would be fine too (I've already searched for extensions on my own but, again, I struggle to find anything with a monthly option).

I found a StackExchange thread talking about it here. Apparently It can be done natively in Firefox, but only via the about:config screen. Which is a bit unintuitive. The Info is a bit old, but nothing says It had been removed since then.
Here is a short summary on how to do it:

1. Go to about:config (in the URL Bar)
2. In the search bar type network.cookie.lifetime.days select Number and press the +
3. Set the Number to 3 and Press Checkmark
4. Type again in the Search bar network.cookie.lifetime.days
5. Select Number again and set the Number to the amount of Days You want to keep them (Needs to be a full number)

I have enabled it today and set it to 1 Day, I will report back Tomorrow if it worked as Intended or if it dident.

It works, my Cookies were gone after 1 Day. Now I am going to incease it to myselft, but good to know that that still works.

A few years ago, before I knew better, I used to have an extension for this purpose where I could also set whitelisted sites that would not get their cookies deleted automatically. I can't remember the extension and wouldn't recommend it, since extensions come with their own load of issues and privacy concerns.
If you decide to use an extension for this purpose (in the case of Chromium) I would recommend to use something like "CRX Extension Source Viewer" to review the source code yourself. And also have something like "Under New Management" to get notified when anything about the author/owner of an extension changes; this should help you avoid trouble in case they sell out and delete the extension before whoever took over can make problematic changes. Beyond that I would use CRXcavator and/or spin.ai 3rd party risk assessments before installing any new extension.

And here my very low tech solution: Just set a reminder to delete them manually once a month. I mean it's not like automating this would save you a lot of time and sometimes I just prefer to have manual control, because it also keeps me aware of these matters and lets me notice possible changes.
In Brave you could also use custom scripts (developer options) but I am not sure whether it would be possible to set this kind of timer or check the age of each cookie individually.

Reviewing the source code won't help for me because that's greek to me.
CRXcavator is under an "extended outage" as they put it
Funnily enough, "Under New Management" gets a poor score on Spin.ai's browser extension checker. A 36/100. So do most of the extensions I already own. Even uBlock Origin! 41/100! This calls into question for me how reliable Spin.ai is?

Now I'm wondering if I should use about:config for Firefox and keep asking for help with Brave (Chromium), or if I need to do it manually like Pearl recommended. I'm hoping there's still something I can set and forget
P.S. I considered moving to Arc browser, just in case that has better options, but I've been lacking the motivation to make the move