Using Ublock, I am able to get this feature... to an extent. Download UBlock origin for Firefox or Chrome.
After that is done you can right click on any item on a webpage and block it.
Right click the youtube bar you want to block, click "block element" from the drop down menu. This will then expand a window on the bottom right of the screen. If you click the text it will highlight the item on the page you are about to block. Currently the item on youtube is called "###masthead-positioner". Choosing "create" will block the youtube bar, allowing you to now scroll down and get rid of the large banner they put on every page. This only works on this page, and will disappear after you reload.
I wish I had a better solution, but this works for now.