This Sunday:
I cleaned bottoms from some green algae on Saturday using my secondary method. The ease of cleaning has not changed over time. The bottoms are clean save for a two small patches I missed. The paint look 100% intact and the mildly hydrophobic behavior is restored after each cleaning. I would guess it would work for at least another season as is. I will, however apply a fresh layer of paint hoping I will achieve a smoother finish this time.
/Martin