It isn't actually about rewards; the reward idea was an example of someone improvising where the normal kaizen method -- namely break the task down into such tiny steps that the first step causes no resistance -- cannot be applied.[*]
The kaizen method (though not called that) uses the same principles as breaking a horse to wear tack and carry a rider. The process is tackled one small step at a time and advancing to the next step is only done when the horse is comfortable with the current step. One of Maurer's examples was getting one of his overweight, stressed and overworked patients to take exercise by asking her to march on the spot in front of her TV for 1 minute a day. This was such a contrast to the advice she normally received from doctors about exercising for half an hour a day and it seemed so silly and easy to do that she actually tried it. Of course it was easy to do 1 minute a day, so she built up the time to 5 minutes and so on until she felt happy enough with the idea of exercise to take on something more conventional.
I am currently applying the kaizen method to my procrastination over the gardening. When I look at the jungle out at the back, I feel overwhelmed and don't know where to start -- so I don't! (I also literally don't know how to plant and grow things and don't at the moment have time to find out.) That's why I have just set myself the task of doing 1 Thing in the garden each day. That one thing can be as small as just walking to the bottom of the garden and standing for a moment to look around, or pulling up one weed. When I feel more comfortable being out in the garden and generally poking about there, I will start to demand more, but that's unlikely to be until at least next spring because other things have higher priority.
[*] If Karen Pryor had used the normal kaizen method of getting used to each stage before advancing to the next, the academic year would have been over and she wouldn't have made it to any of the classes!