I've used a similar approach in the past to get myself to do things. One addition to it I find useful l is to also include a reasonable penalty of sorts for failure. For example, I will study for my test for the next two hours, and if I fail or attempt to weasel out of it, I will eat X amount of spinach. This way, even if you assign yourself an unreasonable goal and fail, you still have to pay a price, so you'll a. Hopefully assign yourself more reasonable oaths in the future and b. The effect of breaking the oath is "lessened" since you are paying a price for failure.