Extension [1] gives a little 'X' beside the channel name in home and search, that can be used to completely remove that channel from all future searches.
Similarly, remove a bunch of random distracting crap[2] such as 'related results'.
[1]: https://addons.mozilla.org/en-GB/firefox/addon/youtube-clean...
[2]: https://addons.mozilla.org/en-GB/firefox/addon/youtube-recom...