I have a Calypso version, which actually bounces the clothes, does a great job on pillows, just make sure there are enough to balance, most bed pillows should be 2 to a load, smaller throw pillows you would want more, for the spin....
I am not sure how the impellor machines would handle these.....
the main concern is saturation and getting out all the trapped air so they don't float......you may have to monitor the machine while in use.....