In my experience, what you've been seeing is very unusual. Everyone I've ever seen do dishes rinses them, every washing machine, whether for dishes or for clothes, has a rinse cycle, sometimes more than one. Soap facilitates cleaning, but then you rinse it away.
You might ask these people whether they do the same when washing themselves. Well, maybe you'd better not, unless you know them really well. It really makes you wonder, though.
That's a very odd thing you've come across. It's usually us that are the different ones.
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"Pack up my head, I'm goin' to Paris!" - P.W.
The world loves diversity... as long as it's pretty, makes them look smart and doesn't put them out in any way.
There's the road, and the road less traveled, and then there's MY road.