Video Blocker allows you to hide videos from channels that you want to prevent your kids or yourself from watching. You can specify these channels by going to one of their videos, clicking the extension at top right of the Chrome browser, and clicking the 'block' button.
If you find any bugs or have any other problems with this extension, please notify me via the support option on the details-tab on this page. It is very difficult to help you out if you report a problem via the comments, since there is no way for me to respond to you.
Good luck and happy video blocking!