Twitter collects all your interests and you can uncheck these on this page https://twitter.com/settings/your_twitter_data/twitter_interests

But there are maybe 1000+ items to uncheck, but no way how to remove them all.

I have created simple bookmarklet.

Create new favorite page (Bookmark - ctrl + D) in your browser and put this string into url field and save it.

javascript:(function(){ let widgets = document.querySelectorAll("input:checked"); [...widgets].forEach((widget) => {widget.click() }) })();

Now go to Twitter Interests page settings and click on your new Bookmarked page (it is called bookmarklet) and voila.