what is the point of doing this, it just looks like a 2 strand twist?
They hold a little tighter & longer (especially if you have hair that poofs)
But they do take longer.
When you look at them side by side next to a two strand twist, you can clearly see the difference.
they are also helpful when you're doing a flat cornrow that you want to end in a hanging twist because you already have 3 strands.
OP, I'm gonna look in your fotki to see if I can determine what went wrong but my guess is that you didn't really twirl each strand as you were twisting, I have a sort of demonstration of that method in my fotki videos but it wasn't with 3 strands it was 2...same theory though.
I will try to post a 3 strand twist tutorial soon because they work well for me when I do them.