> I want to say I take your point. I wouldn't use this in formal writing, but as far as I can tell this is an accepted western way to emphasise something.

No, it isn't. Using "them" in the way you did makes you sound like a hillbilly.

Just some advice: it's wise to avoid using any words or usage listed in the dictionary as "dialect" unless you're very familiar with the particular dialect it's from. Likewise, you should be very careful with "informal" terms unless you've actually been introduced to them informally by someone who knows how they're used. There's a lot of cultural context that needs to be mastered with those, and you won't learn that from a book, let alone a dictionary.

I saw the dictionary entry. Still, take it from a native (US)speaker. The only time you would want to use it is either in jest, or to sound like an uneducated hillbilly.

*edit - I will add that the 2 youtube videos are not good examples to be learning english from...

I would like to amend my above comment: the 2 youtube videos are HORRIBLE examples to be learning english from.