If akratics reliably would take such a pill, wouldn't you expect self-help to work?

My own observation is that people generally stop using self-help techniques that actually work, and often report puzzlement as to why they stopped.

So I think akratics would take such a pill. The catch is that self-help is generally a pill that must be taken daily, and as soon as your brain catches up with the connection between taking the pill and making progress on a goal you don't actually want to make progress on... you'll start "mysteriously forgetting" to take the pill.

The only thing I know that works for this sort of situation is getting sufficiently clear on your covert goals to resolve the conflict(s) between them.