We used Defy Marine finish on our 6-month-old pt decking that gets full sun from noon till sundown. Over a 4-day weekend, used the cleaner, then the brightener. Followed all directions explicitly. Two weeks later we returned to the house (summer home right now) to see white stuff covering the knots. We scrubbed--not too hard--nothing changed. Is there anything anyone knows of that will get rid of this white stuff? Sadly, there are quite a few knots on this deck so now it looks polka-dotted.