I use coral skeletons in my tank and bleach them periodically. I use about 1 cup in a 5 gal
pail and leave them overnight. I then rinse completely and place them back in tap water with a good de-cloranator. Then I let them air dry completely. In the summer sun dried is the best. This seems to work well for me and I have never had an issue. In between They tend to turn slightly brown and I just rinse them in fresh water which takes most of this off.
Hope this helps,