Stop Messenger App from opening at Login

In response to https://discussions.apple.com/thread/252869510?login=true which is too old to reply to now, I tried all suggested steps and none of them worked, then through trial and error I found a solution which works and so far has caused no functionality problems with messenger. Why it was this convoluted rather than just a case of removing it from 'Login Items' in settings is beyond me but here we go:

1. control+click on 'Messenger' in applications using finder
2. click 'Show Package Contents'
3. Click 'Contents' then 'Library' then 'LoginItems'
4. Delete 'Messenger Login Helper'
5. Restart mac and voila
6. Eat a celebratory slice of toast with your favourite spread