Before I brought my tank home and converted from fish only, the maintenance guy used to bleach (soak) all the rock every two weeks, in a tall garbage can, then he would empty the water and use a neutralizing solution (don't remember what it was), the whole process took about an hour and removed all algae. did not seem to affect the bacteria or bioballs and he did that for 6 years.
The previous guy did it without neutralizing and killed 90% of my fish then tried to correct it by bringing me about 20 fish which caused the tank to bounce killing all of them... he was a real moron and made me not want a tank.. very sad days back then.