For some, using more water is a way to hide the taste of MMS1/CDS/CDH. At higher doses adding more water to a dose may help relieve throat irritation due to higher amounts of CLO2, especially from CDS because it is fully activated externally.
Mixing more water with your dose just dilutes the CLO2; you will be getting all of it when you drink the entire amount. How much water you use is up to you.