I personally wouldn't recommend it still.what if it is done outside?
What are the options for "bleach the rock, soak in hypersaline water"
For bleaching the rock, you would put it in a bucket of bleach mixed with water, let it sit for a while, pull it out, air dry it for 24+ hours, then rinse it off.
For soaking in hypersaline (very, very salty) water: soak the rock in the hypersaline water for a while, pull it out, rinse it off, and I'd let it air dry for 24+ hours for good measure.