You're on the right track anyway. Water, as we all know, is H2O. That means it has two hydrogens and one oxygen. Thus the chemical name is Dihydrogen Oxide.

Here is a good web site on chlorine dioxide.
http://www.lenntech.com/processes/disinfection/chemical/disinfectants-chlorine-dioxide.htm
Long story short, it readily decomposes once it reacts. Thus there is nothing left.

Bleach can (and likely will) produce NaCl (salt, laundry bleach ) or CaCl2 (calcium chloride, pool bleach), a different type of salt. Other undesireable by-products are also possible.
http://www.lenntech.com/processes/disinfection/chemical/disinfectants-sodium-hypochlorite.htm
Long story short, bleach can (not necessarily will) produce some undesireable by-products. Also, both sodium hypochlorite and chlorine do not deactivate Giardia Lambia and Cryptosporidium.

Check out this link for some more good information.
http://www.lenntech.com/processes/disinfection/chemical/disinfectants.htm