Maybe I'm just dense but it appears this technique can only be used by those who have already purchased the reloadable cards previously?

I looked around and every link is either dead or takes you to a login page to myprepaidbalance.com which requires you to already have a card just to sign up.

So it looks like the headline in the wiki:

"UNDEAD - All Cards for Sale Online Were Pulled By MetaBank, But Some May Once Again Be Available (see #374)"

May be incorrect.