Comment by Pazzaz

I think you're exaggerating a little when you say "site:youtube.com" doesn't work. If I search 'site:youtube.com apple watch' I get 143 000 000 results, and if I search something more specific like 'site:youtube.com "Featuring Dr James Grime"' I'll find exactly what I'm looking for. But you're correct that it doesn't seem to search video comments, only titles and descriptions.