Question for people who sleep like this: do you live with anyone? How do they tolerate it? I can't imagine it's great to wake up to your roommate scraping pans in the kitchen on odd nights.
I do not. And no, it isn't.
My dad, I think, had occasionally polyphasic sleep, and he often took on-call rota slots as a result. He'd be in the kitchen cleaning, or in his study, but since the house was big, it was rarely a problem. Sometimes he'd be napping in his study, and I know he slept easily on the train to and from work (with an efficiency that meant he woke up a minute before his stop on the way home).
When I was a student I just forced my polyphasic sleep periods into normal sleep as best I could, which typically manifests a bit like delayed sleep phase; by the middle of the week I was two hours behind everyone else, and I actually did worse in the courses that had early Friday lectures. But when you're a student, being awake or asleep at odd hours is normal enough not to be remarked upon.
As a programmer, polyphasic sleep is sometimes unnoticeable to others. These days probably more apparent in git commit logs.
Bigger, and well built dwellings help, as do earbuds and soft shoes.
So some tasks you do in that period of time are done with a kind of lower level of objection, easier "starting", and in a contemplative start, and you're not actually tired.
Which is what also gives this "cleaning fairy" sense that nobody in particular did it.
I tried it and it worked, but I have a family and no, it didn't work for them, so I stopped. Couldn't get a schedule right that allowed me to be with the family for normal social interaction times, AND be at work when THEY expected me to be available for the work-team.
So I had to go to a socially acceptable "norm".