Clean YouTube Watch Later Videos

youtube_clean_watch_later_videos.js

// Version 2.0.1
// This script will remove all videos from watch later list 
//
// Usage
//
// #1 go to https://www.youtube.com/playlist?list=WL
// #2 run following script in your browser console
(async function() {

  const playlistName = document.querySelector('.metadata-wrapper #container #text')?.textContent || document.querySelector('#text')?.textContent
  if(!playlistName) {
    alert(`Couldn't determine playlist name!`)
    return
  }
  
  if(!confirm(`Are you sure to delete ALL videos from ${playlistName}?`)) {
    return
  }
  
  console.info("start...")
  while(true) {
    const videos = document.querySelectorAll('#primary ytd-playlist-video-renderer')
    if(videos.length == 0) break
    
    for (let videoElement of videos) {
      const videoTitle = videoElement.querySelector('a#video-title')
      console.info(`Remove Video\n`    
        + `  Title: ${videoTitle.innerText}\n`
        + `  URL: ${videoTitle.href}`)

      const actionMenuButton = videoElement.querySelector('#menu #button')
      console.debug("click actionMenuButton", actionMenuButton)
      actionMenuButton.click()

      const removeButton = await untilDefined(() => document.evaluate(
          `//tp-yt-paper-listbox/ytd-menu-service-item-renderer[./tp-yt-paper-item/yt-formatted-string/span[text() = '${playlistName}']]`,
          document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue)
      console.debug("click removeButton", removeButton)
      removeButton.click()
      
      await sleep(200)
    }
  } 
  console.info("done!")

  // === util functions ========================================================
  
  async function sleep (timeout) { 
    return new Promise(res => setTimeout(res, timeout))
  }
  
  async function untilDefined(factory, checkInterval = 100) {
    while (true) {
      const value = factory()
      if (value != null) return value
      await sleep(checkInterval)
    }
  }
})();

I've been testing my fork for few months that does not require lang specific options and modifications, could use more people trying it, also it's a Violentmonkey script
https://gist.github.com/sandorex/6bdd51ef467a079c87f19ba469a8bc7c
Feel free to take the code if you want

@sandorex thanks a lot, I've updated my script to your provided solution to get rid of language specific configuration.

It seems youtube did something so the script broke a bit, change

const playlistName = document.querySelector('.metadata-wrapper #container #text')?.textContent

to

const playlistName = document.querySelector('#text')?.textContent

The id stayed the same for a while now so im hopeful it wont need more fixing for a while 😄

@sandorex thx a lot, however for me it' works as expected with document.querySelector('.metadata-wrapper #container #text')?.textContent

Weird it works for me now too, it did not work yesterday for some reason

thank you