Seems to me a good antifoul doesn't eliminate the need for a good bum scrub. It may increase the interval a small amount though.
The real and practical benefit is removing the growth is much, much easier. Which at my age means I can free dive the job myself. An important consideration on my budget
I've no proof of this, but it seems the larger the barnacles get the weaker the bond becomes. Could this be from copper diet? Also the color of the barnacles seems to shift towards a grayish look, as if they are dying.
My first haul out
was in January. Spent several hundred dollars on paint
and did the work myself. A few weeks after splash I doubted the need for paint until I dove and wiped barnacles off with a gloved hand.