I found this handy search engine for finding youtube videos that say a phrase or word you’re looking for. This is how you search youtube captions.
Website: filmot.com

If you’re wondering how to use FilmOT.com, it’s really easy. It works like most any search engine you’ve ever used. The difference here is you’re searching captions created automatically by youtube, or submitted by the content creater, to find a video that says the word or phrase you’re looking for. While I use this captions search engine to find videos I can trim clips from to use in my own videos, this can also be handy for simply browsing youtube for content you’re looking to watch.