http://www.learn-and-play-online-chess.com/keonihiva-gambit.html
How many unknown openings are there?

There are two problems with the OP's post:
1) Nobody cares! It is, as you said, hot garbage. Why would anybody waste their time on such bulls**t? I'd rather spend my time studying the Polish, French, Dutch, Strategy, Tactics, Endgame, GM Games, etc, not this "brown stuff".
2) The subject line is an unanswerable question. To answer a quantitative question, like how many of anything there is, those items you are counting must be known. That's like saying how many unknown types of bread are there? We all know, even children, about White, Wheat, and Rye. So they are clearly "known". Well, before you can count pumpernickel, you'd have to know what pumpernickel is, that it is a bread and not a car or tree or state capital. Once you know it is a bread and you start to count "one", you are actually back down to zero because now you know what pumpernickel is, that it is a bread, and you are still at ZERO unknown breads!
So earlier today I was having some dumb fun trying to find unknown and stupid openings, and I came across this. The Delayed Keoni-Hiva Gambit. I'm absolutely sure you have never seen this in your life, despite (atleast on Chess.com) it being officially named.