These are fun. They take a lot of 'research' to do. I have to watch several videos with the audio turned down and the CC (Closed Captions) on. I would say about 2-5% of what I watch reveals any funny content at all, so it's time intensive.
I find most non-American accents are the best for hilarious mistranslations. Though there is Stella Rae who has a very american but also very slurred speaking style surprisingly can turn up some funny captions.
What i look for: there needs to be a funny coincidence in timing, oddness of the caption. Occasionly there are very R-rated captions that i ultimately feel i have to cut because i aim for Vegan Funny being a family friendly channel, but we'll see how it evolves. For example i haven't shown any factory farm horror footage but that may be around the corner. The point of the channel is comic relief from the seriousness of the vegan topic: to poke fun at ourselves. But i do have a couple skits in mind that are more 'political' or harder to swallow because the message is very serious though couched in humor.
