Bleach is good, but it will not remove certain things such as bound copper, or bound inorganic phosphate. It should remove organics well though. If you want to do it fast and get rid of everything, the most efficient way is bleach then acid. You can do 1:10 bleach : water in a bucket, with a powerhead for 24hours, then rinse very well. From there go 1:10 muriatic acid (from a hardware store and remember add acid to water and do so slowly). You can leave it for 20 minutes or so. Some people do longer, up to 3 hours, but this shouldn't be necessary unless the rock is really bad. You can neutralize the acid with backing soda, then rinse very well. Wear gloves and goggles though. And don't do it on your living room floor LOL.