One very important component of the Unimac's spin spray rinsing is the water filter. The spinner water line has a very good filter in it to keep the minerals and stuff in good water from being filtered through the clothes which leaves terrible streaks. Also, that spinner tub is in a large compartment which allows the resulting suds and water to be thrown far from the spinning basket so that it is not slowed. Perhaps the main reason the Unimac can get by with just spray rinsing is that the fabrics are lifted from the wash water and placed in the spinner, leaving heavy soil particles behind. The removal of heavy soil in this process is not dependent on draining and straining the wash water while the fabrics are in the tub. The Collapso was very bad with pet hair because there was no way for it to float off while the fabrics were surrounded by water. Of course, if pet or body hair is not a problem, that type of cleaning system works OK.
I do some spin spraying to suppplement the deep rinses when I rinse in one of the top loaders. I use one of those plant watering diffusers which create a soft "rainfall" type of spray which does not bounce off the fabrics and yes, the spray has to be focused on the spinning load. The spray has to be held so that the water flows onto the fabrics in the direction in which they are spinning, not just downward from an overhead shot. The Unimac's dedicated spinner tub with the water inlet in the center of the top is far more likely to give dependable, uniform rinsing than most top loader sprays. While the spray rinse provided between the wash and rinse in the Maytags and my older KitchenAid is effective for preliminary flushing of the machine and the load, I have found it is best not to dilute the detergent solution in the fabrics too much before the deep rinse so that enough detergent remains to flush the soil from the fabrics and keep it suspended in the rinse water before it is drained away. After the rinse, in the final spin, is the best time for final dilution of any remaining cleaning products unless the wash was way over dosed with detergent and suds are a problem. The most efficient spray rinsing also requires that the clothing be in as thin a layer as possible which is why the spin/drain in the Maytag is desirable and is why I interrupt the drain in the KA to create a spin/drain in it.
It must have been here that I saw a link to a modern front loader that gave the spinning load fine sprays to help remove detergent. When I washed a huge load of 8 bath sheets in the Duet yesterday, I used Arm & Hammer HE detergent. After it started to spin, a remarkably well-balanced spin, it stopped because of suds between the basket and outer tub. I opened the dispenser drawer and used the hose connected with a Y to the extra hot and cold faucets to introduce a small flow of cold water into the machine. It helped with the suds in the sump and I was quite surprised that the flow of water provided a bit of spin rinsing as the load began to spin again. I was only trying to flush suds so that it would spin. After the first spin, I rinsed the load in the KA then spun 4 at a time at 1600 rpm in the W1918.