This technique will cut your deep cleaning cycle to near zero. Note that this technique isn't worth a damn for decks because the foot traffic and general abuse of a deck will wear out the sealer rather rapidly. The technique is best reserved for covering boards. Have a canvas drape made with sand tube ends, to drape over the area of the covering board where everybody steps to come aboard. Keep your brite work teak Chamoised down.
Water spots are chemicals and minerals in the water that are left after the water evaporates.
These little demons, under direct sun light, literally eat their way into the finish. Hopefully, I've offered some insight in this article and you may find it useful.