Alright, I hate when people do this to me, but I'm going to do it to you anyway, please forgive me. I'm only trying to help. I am going to give you a total non-answer in an attempt to do an end-around to get at the heart of your problem.
Bryopsis won't grow unless it has nutrients to fertilize it. You need to eliminate any source of nitrates or phosphates that are feeding it. By killing it off the rocks you have now, you are only treating the effect and not the cause.
I only say this because I just recently began winning my own battle with bryposis and hair algae. I tried to fix the problem by throwing money at it. I bought an urchin. Concurrently, I decided to change the way I fed. Now, instead of feeding twice a week, I feed less quantity more frequently, making sure that every bit of my last squirt from the turkey baster gets eaten before I give it another. This resulted in the bryopsis turning brown and shriveling to its death before the urchin even had a chance.
my $(1/50)