Can you elaborate on why it's idiotic? As much as computer programmers like to think they're precious snow flakes to whom productivity tips don't apply to, this sort of system works for fitness, sales and from PGs post, sculptors.
Because as a one-time experiment, the subject is likely to do well as the phenomena itself is new. As the experiment progresses into multiple days or weeks, the subject is likely to say, "What the fuck? Stop slapping me. You're fired, I want to browse reddit." In my opinion, anyways.
I think anyone willing to pay someone ~$300 a week will not simply snap at the person and fire them because they want to browse reddit. They understand the value.