Scrapy browser console script to unfollow all the podcasts on Overcast website (https://overcast.fm/podcasts)

unfollowAllPodcasts.js

function getPodcastIds() {
    var feeds = document.querySelectorAll(".feedcell .art"),
        i, ids = [];
    for (i = 0; i < feeds.length; ++i) {
        let anchorElement = document.createElement('a');
        anchorElement.href = feeds[i].src;
        ids.push(anchorElement.pathname.split('/').pop().split('_')[0]);
    }
    return ids;
}

function unfollowPodcast(id) {
    fetch("https://overcast.fm/podcasts/delete/" + id, {
        "method": "POST",
        "credentials": "include"
    });
}

function unfollowAllPodcasts(ids) {
    var i;
    for (i = 0; i < ids.length; ++i) {
        unfollowPodcast(ids[i]);
    }
}

unfollowAllPodcasts(getPodcastIds());