I don't think so (I looked). Best I could find was some articles online claiming you can add "-unwantedChannel '...'" to your YouTube search to exclude individual channels. I didn't even test it because it would be WAY to cumbersome. Maybe that's all Channel Blocker does under the covers -- add a bunch of those switches to my search.
What frustrates me the most is that this is one place where mine and Google's interests actually align! Let me help train them to not show me crap I don't want to see... then I'll use their products (YouTube and Search) more and give them more opportunities to show me ads! (Well, theoretically -- I block as many ads as I can right now).
That was one of the big reasons I looked for an alternative to Google search. IIRC, you used to be able to exclude results from Google search. In order to do so, you HAD TO LOGIN TO GOOGLE (another huge win for Google!). Now I use Kagi -- primarily because they allow me to exclude sites from their search results.