Add hateful, racist, viral words to the blacklist. You could also add user names to block comments.
As you know users can delete any of their comments and comments left by other users on their channel. Users cannot delete comments left by other people not on their channel, however they can report any inappropriate comments on any channel if they are spam or an insult (this will hide the comment from view).
Now you can use this extension to hide inappropriate comments on your computer!
It is very easy to do - add to the the black list words or username whose comments you do not want to see, after that Clean Youtube will automatically remove all comments containing words from the blacklist.
Add hateful, racist, viral words to the blacklist and you will be sure that your child will not read comments with this words!