honestly, when the majano dominate the tank, there is nothing you can do anymore.
i have battled the pest for almost two years, and tried every fish, mentioned in literature, where is the smallest chance that they would eat majano, but eventually broke down the tan. I flushed it for four weeks with rain water, and rebuild the tank with fresh live rock.
everything infected with the majano pest went in the trash bin.
it is a drastic decision, but putting effort in it, month after month, without result, and corals starting to bleach because the sting cells of the majano poisson the water is worse.
greetings
joachim