Eugene:
My experience with the GE FilterFlo was when I got one in 1993 -- it had a white-on-white control panel, but it was I think the last model they made, I believe it went to a rim-flo (like the Hotpoints) and by 1995-96 or so they had already gone to the 3-something cubic foot basket with a dual-action agitator.
Basically you were supposed to put the mini-basket in, load it with the garments to clean, put the filter on top. Then you'd select a "Mini-Basket" water level, if I remember correctly. Set the SpotScrubber knob to "On", put on detergent, select water temp and set the dial to a cycle that I believe was also called SpotScrubber.
The machine would fill to the lowest level, and start agitating -- the pump would send water to the filter, which would then fall into the mini-basket; one of the main differences was that the machines with SpotScrubber had a "solid tub" mini basket, the water could only leave/overflow thru the top holes. Other models had mini baskets with both top holes and holes underneath.
Anyway, as the washer pumped the mini basket full, the "SpotScrubber" knob would count down a minute or two and then pinch a rubber hose that led to the filter, thus stopping the flow of water and keeping the concentration inside the mini basket higher than usual. When the machine started spinning, the SpotScrubber would advance to "Off" and let water overflow when the machine next filled for the two automatic rinses. The spray rinse could get rid of the suds lock, but the load inside the mini basket depended on the two deep rinses to let go of the detergent.
In my experience, it worked really well, but then again the machine washed really well anyway if you had a good detergent with enzymes and hot water. I did put it to use when a housemate got ink all over a couple of his shirts and the SpotScrubber did remove the ink stains. And another time a t-shirt got bleach spots on it accidentally, so I put it in that cycle with the normal amount of bleach and it all faded to a nice tint and no bleach spots. I ran a third rinse with vinegar to neutralize the bleach and got a nice t-shirt to wear for a bit (the bleach naturally weakened the cotton at that concentration, but I didn't care because the t-shirt was useless in the spotted state).
All things considered, I really loved that washer and dryer set, they had a lot of things done just right. As for the downsides, one was the noisy operation and two the unbelievable amount of water/energy it consumed, because they basically took an old design (solid tub) and just removed the solid tub and put a perforated basket in there, I think there was a gap of about 2-3 inches between the basket and the outer drum.
I was sad the day we had to move to another apartment and the washer wouldn't fit thru the new apartment door by 1/4 inch. We sold the set to friends who used it for more than 10 years and got the new GE with the plastic tub and dual-action agitator. Did not care for that one, when we moved we left it behind and I believe the landlord told us it did not survive another 3 years.
Hope that helps, if you have more questions I'll try to answer them later.
Hugs,
-- Paulo.