This weekend I also noticed something else that I found interesting.
Pouring water into a spinning spin tub (1400 - 1600 rpm) does not really do the trick in terms of a good extract-rinse. Reason is, the water centrifuges out before it has a chance to soak through to the clothes at the bottom of the tub.
So the question for people who have Hoovermatics and suchlike, with the continuous rinse/spin function: How much water and how fast does it pour in there; and have you noticed whether the clothes at the bottom of the spin tub have gotten their fair share along the way?
Also, pouring water into clothes that have spun out but are still in the spin tub, is a big no-no: consistently produces a serious out-of-balance where the spinner bops against the wall of the spin tub (which, needless to say, I open the lid to shut off immediately this starts to occur).
However, what does work is to take the clothes out of the spinner and soak them in another container (with or without agitation), and then put them back in the spinner. That consumes minimal water and results in a decent extraction such that the final rinse water is much less cloudy than if this procedure wasn't done.
Design implications:
The vertcal-axis automatics that use a spin/extract cycle where water is sprayed at the agitator as the tub is spinning, are definitely on the right track here. Spraying water onto the agitator does the best possible job of getting it to splash out evenly across the clothes that are stuck via centrifugal force to the sides of the spinning tub, so the extraction is as evenly distributed as possible.
For comparatively smaller diameter high-speed centrifuges generally, whether in twin-tubs or in stand-alone units, a vertical tube at the center of the spin tub could be provided, with perforations, and with means of introducing water through the tube. A relatively narrow-gauge tube could be used, with perforations, and with a non-pressurized or neutral-pressure water inlet. Water would enter the tube at the rate at which it was sucked out by passing into and through the clothes as they spun.
Given the speeds and inertial masses involved, this is not an experiment I'm likely to try

.