It's not a new scheme, it's exactly how that "one online gambling site" does it. I wondered how they did it, so I figured it out, replicated it and wrote a blurb about it.

It's a pretty neat trick to extend the "all or nothing" property to multiple transactions. For some very limited use-cases (like my admittedly contrived example), this is exactly what you want. Usually it's not. Usually you just have to wait.

Honestly, bitcoin is not really suited for instant gratification things.