I tried it for the first time today as well, just on a whim. I ended up counting to seven hundred something breaths. At two specific points I felt a kind of spinning/rushing sensation, but I got so excited about it that I couldn't quite fall asleep. In fact, during the whole WILD attempt, my heart rate felt like it was through the roof. It's just my luck.

Oh well, we'll both keep trying, perhaps with other methods.