John, I don't know if this is of any use ...but my 26, Elsa, dries in mud almost every tide. I never had any serious problem with erosion for the many years that I used International Micron Antifouling and then subsequently the much cheaper Plastimo equivalent.
Last year however I couldn't get the Plastimo one and was recommended Teamac eroding paint. The Teamac is so soft by comparison that serious erosion has taken place this last season. It does leave less to scrape off and I have had problems with serious build up of paint with the previous two types .. so, inevitably you win some and lose some .... but it could be that you need to find a more robust paint?
I would be interested in your comments as I may have to go back to the very expensive Micron to solve the problem myself.
Chris.