People who do a lot of exercise do have a plan similar to what you described, it's called CKD (cyclic ketogenic diet, I think).

Are you prepared to do some heavy weightlifting and such?

You'd probably have to only eat the right things at the right times on that plan. There is a forum for it.

But for most of us, eating carbs for a few days totally sets us back weeks in terms of losing weight.

Some people have no problems drinking coffee. The idea is that the caffiene in coffee can act as a stimutant to your insulin levels making you hungry or crave things. You should see how your body reacts and take your cue from that.

Beth