Well, I did a little of both. A couple weeks I was strict and ate just whole wheat bagels, oats, sweet potatoes, and such all day long. But a couple weeks I did splurge and have pizza for dinner. Any time I ate unhealthy on the carb-load day, it was only at dinner - I found it easy to stick to clean carb sources during the day.
I believe one of the biggest keys to success is how well you do in the glycogen depletion phase just prior. If you're fully depleted, then even if you eat somewhat dirty carbs, you have a much higher chance of nutrient partitioning and all those excess calories going to refill glycogen stores, etc. If you DON'T do a good job with your depletion, you have more of a chance of spillover into fat stores.
Have you read his Ultimate Diet? I believe it's a superior method to most carb-cycling methods due to the training that goes along with it. But it's not for the faint of heart - it's a rough routine to stick to.