Most of water is used for technical purposes, not for drinking. Like washing hands, body or dishes. If it's safe for that, that would be huge achievement is this process is cheaper than conventional methods.
I'm not sure how practical it is to have two classes of water for different purposes though, given most buildings come with only one set of pipes.
There's also other non-domestic uses that could greatly benefit from cheap large-scale desalination: Agriculture in arid regions. Sea water is not an option, but taste is not a primary concern.
Taste might be a concern if the chemicals pass in the edible parts of the plants.