Sodium percarbonate is a great chemical to use to clean out your brewing equipment. You can just mix a little with water and soak your tubes, bottles, carboy, etc. for an hour or so to get them squeaky clean.
What is it? It is basically dried hydrogen peroxide in granular form with a molecular formula of Na2CO3 · 1.5H2O2. So it is just sodium, carbon, oxygen and hydrogen. It is fairly safe, doesn’t smell or create toxic fumes, it breaks down into water, oxygen, and soda ash, so you can pour it down the drain, and it is much more environmentally friendly than bleach but does the same job. It removes the film that can slowly build up on your equipment that doesn’t come off with iodine and that is hard to brush off. It is also inexpensive.
Read more about it at this website (devoted to using hydrogen peroxide! LOL): http://www.using-hydrogen-peroxide.com/sodium-percarbonate.html