1 and 3 seem too easy to inflate, but 2 is a good idea. Instead of blocking specific websites, write a program that passively measures how much time you spend there, and compete with other people to get a low score. Maybe everyone puts some money in the prize fund...
A lot of anti-akrasia recipies rely on good faith to some extent, so I don't think it's a huge problem (implementing those and getting enough people to use them would be a much bigger hurdle!). If some people want to cheat themselves to stop improving themselves, hey, their loss.
Procrastination could be described as the short-term mind vs. the medium-term mind, and cheating would often require a minimum of planning and of thinking beyond the long term - precisely the stuff that the short-term mind doesn't do.
Here's an internal dialogue I just had.
Q: How do we test rationality skills?
A: We haven't come up with a comprehensive test yet.
Q: Maybe we can test some part of rationality?
A: Sure. For example, you could test resistance to akrasia by making two contestants do some simple chores every day. The one who fails first, loses.
Q: That seems like a pointless competition. If I'm feeling competitive, why would I ever skip the chores and lose?
A: Whoa, wait. If competitiveness can cure akrasia, that's pretty cool!
Now we just need to figure out how to make people more competitive in the areas they care about...