Given I have no problems enforcing daily habits on myself, most of your post is cruft for me. I'll reply to your boiled-down post:

I suspect meditation itself has a conscientiousness-increasing effect, mainly from making you allocate five minutes a day out of your time, but also because I think the relaxation might help in nonspecific ways.

I'm unclear on what you mean by "increasing conscientiousness." Are the non-specific ways necessarily non-specific? Can you cite any abstract benefits of daily meditation?

I suspect the "choose-your-own-adventure" precommitment and then following the directions also work to increase conscientiousness (while reading the article, at least). I am getting you to "buy in" (precommit) to doing what I tell you to do, and then following the steps is allowing you to experience the feeling of being conscientious in hopes that you can tap into that feeling later on.

"Suspect?" Is this a hypothesis? Is LessWrong the best place to gather subjects to conduct the experiment with?

As I see it, you post doesn't have the "mystique" surrounding it to derive the effect you're trying to achieve. Not not be harsh, but I expect this experiment to flop; there simply isn't enough intrigue here. This doesn't feel like it's ready to present to LessWrong—unless you have more to say about meditation.