A bookmarklet to automatically remove privated, deleted, and watched videos from a YouTube Watch later playlist.

yt-remove-unavailbe-videos.js

javascript: (function(){
    let success = true;
    const interval = setInterval(function(){
        const progress = 'contains(@style, "width: 100%;")'
        + ' or contains(@style,"width: 99%;") or contains(@style,"width: 98%;")'
        + ' or contains(@style,"width: 97%;") or contains(@style,"width: 96%;")'
        + ' or contains(@style,"width: 95%;") or contains(@style,"width: 94%;")'
        + ' or contains(@style,"width: 93%;") or contains(@style,"width: 92%;")'
        + ' or contains(@style,"width: 91%;") or contains(@style,"width: 90%;")';
        const menu = document.evaluate('//*[*[contains(@class,"ytd-thumbnail")]['+progress+']'
            + ' or a[@id="video-title"][@title="[Private video]" or @title="[Deleted video]"]]'
            + '/ancestor-or-self::div[@id="container"]/../../div[@id="menu"]//button[@id="button"]',
            document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
        if (menu == null) { return clearInterval(interval); }
        menu.click();
        const remove = document.evaluate('//*[@slot="dropdown-content"]//*[@role="listbox"]'
            + '//*[@role="menuitem"]//*[@role="option"]//span[contains(text(), "Remove from")]',
            document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
        if (remove == null && !success) { return clearInterval(interval); }
        if (remove != null) { remove.click(); }
        success = remove != null;
    }, 1000);
})();