Chlorine bleach is a volatile liquid that should only be used in well-ventilated areas. You know this if you have ever choked on bleach fumes in a closed laundry room. When it comes to keeping a rooting box clean, it has no rival for the home gardener. Mix a solution of 1 part bleach to 9 parts water in a plastic container, but only mix what you need right then. Despite the lingering odor, bleach has a half life of 2 hours. That means it loses half its effect and is useless 2 hours after it is mixed with water. Soak whatever it is for 30 minutes and then rinse with water. The clean is great, but bleach is tough on skin – please wear gloves when mixing and using bleach!