A substrate treating appliance utilizing a plurality of different chemistries for different cycles or different wash loads with a plurality of receptacles for receiving a plurality of cartridges containing the different chemistries. Each receptacle has one half of a lock and key connection arrangement providing a unique interconnection configuration at each receptacle, relative to the remaining receptacles, permitting only a selected type of chemistry cartridge to be accepted at a particular receptacle. A connection effected between the cartridge and the receptacle occurs by rotation of the cartridge relative to the receptacle between an insertion orientation and a locking orientation. Each receptacle is shaped to receive a cylindrical mouth wall of a particular type of chemistry cartridge. Each receptacle may also be uniquely sized, relative to the remaining receptacles, to accept only a selected type of chemistry cartridge. The plurality of receptacles may be arranged adjacent to one another with each cartridge having a configuration that prevents insertion of a cartridge into a receptacle unless every cartridge located in an adjacent receptacle is rotated to the locking orientation.