Properly designed, such as by using cool water to condense the water extracted from the dryer,(this provides a “vent-free” dryer), and then using that now warmed water for the next load, could give an astonishing efficiency.
Decades ago, we had water-saver washers that used one load’s rinse water as the wash water for the next.
Have we stopped thinking since then?
I think we’ve stopped thinking “efficient” and headed off for “the easier, the more often it will become obsolete.”
Sounds clever! I like the idea of extracting the heat and moisture from the dryer to use on the washer, too.
The county seat (Monroe) has enacted water usage limits with *large* fines if citizens go over the limits, which are set by household, no matter how many people are at the address. Fortunately, we're not in that situation here, yet, but I suspect it's coming.