A script to execute in the Browser DevTools Console to slowly clear out your Watch Later playlist

youtube-playlist-cleaner.js

function openMenu() {
	var items = document.querySelectorAll('ytd-playlist-video-renderer > #menu button');
	items[0].click();
}

function clickRemove() {
	var menuItems = document.querySelectorAll('tp-yt-paper-listbox > ytd-menu-service-item-renderer');
	menuItems[2].click();
}

setInterval(function () {
	openMenu();
	setTimeout(function () {
		clickRemove();
	}, 300);
}, 750);