Pulling the fuse causes a reset of the PCM memory which clears all adaptive learnings stored by the PCM (it uses a neural network that monitors and adjusts engine/trans performance). Pulling the fuse is one way to accomplish this as the memory used to store adaptive information is volatile. For example, if you installed a CAI/exhaust/plugs resetting the PCM will allow the neural network to quickly develop/relearn new fuel trimming, timing...etc.
Pointless to do. The PCM catches up within 20 miles or so. I know from having my battery disconnected for a few days and having the car relearn... it was much slower during that time.
I think this is only effective if you usually drive normally, and want a more radical experience for a short time. If you go back to driving normally again, it will soon relearn normal. A Guy