Salt-Away Mixer Unit for Inboard/Outboard/Jet Engine Flush Salt-Away's Mixing Unit is the most popular way to dispense the Salt-Away Concentrated formula. The receptacle holds 6 fl oz (177 ml). Constructed with a 3-position valve (Off, Rinse, Salt-Away) The Salt-Away Mixing Unit was used in the vast majority of the testing performed in the development of Salt-Away.