They are each great for what they do. CS will kill any pathogen with which it comes in contact. Miracle-Mineral-Supplement is able to piggyback on red blood cells; and therefor able to get to more places and make more contact. Miracle-Mineral-Supplement can replace ozone therapy. Miracle-Mineral-Supplement is cheap when you consider that one 4 oz bottle will last nearly a year. MMS is a serious chemical, chlorine dioxide. CS is a harmless metal. They are each safe when taken in the quantities prescribed in their protocols. You will find articles, about chlorine dioxide, that may scare you away from MMS; but the protocol is very safe. No one has complained of any problem other than detox symptoms due to very quick die off of bad pathogens.
CS has a long and great history. MMS is new.
There is no reason why you should want to take both as therapy; however, there is no reason to worry for taking both. With CS, you will want to take probiotics to replace the good pathogens destroyed by CS. MMS "supposedly" does no harm to good pathogens; however supplementing with probiotics will not hurt that protocol either.