How do I clean out a fish tank with a water/bleach solution?

I need to know how to clean the heater, I think we used to have columnaris in our fish tank or some other kind of fungus, and we're breaking it down to clean with bleach and water. So we have to wipe the inside of the fish tank with the solution, soak the siphon in it, and then drop some of the solution in the filter? Anything else?