No, Spirit doesn't mean you will have to flush every two weeks. Everyone is different. It took me many flushes before I was stone free. I went ahead and did two more flushes to make sure it was true.
Now, I plan on flushing on the "maintenenace plan." Maybe twice a year or so.
It was so sad for me not to see those stones anymore. Flushing had become such a part of my life and I looked forward to it, so when I began to see less and less stones, it was really a bummer for me! Now, I live my life through others who are now flushing!