I usually hookah dive and clean the slime off my hull every 2-3 months. Then use a magic eraser pad to clean up the waterline.
On a whim, I tried the magic eraser below the waterline on Artex 5+ antifoul on 3 month old heavy slime with no hard growth.
I used to use a soft bristle brush or occasionally a gloved hand. The magic eraser wiped off the slime first wipe, the job took about 3/4 of the time and was undoubtedly the most though clean I have done.
Last year I painted my antifoul with 3 different colours so I can see how much wear there is on the antifoul. The magic eraser didn't do through the upper layer,
Try it, it seems like a winner.
