Never boil live rock, just imagine what would happen if there was a zoa on it? Well you dont have to, the owner at my lfs
learned his lesson, he boiled 10lbs of rock because it had alot of hair algea on it like yours, turned out there was a head of zoa on it and when i boiled released poison into the air. He was in the hospital for 2 weeks. Put it in a bucket of SW
with a powerhead and heater. Leave it for 2-4 weeks.