Back in the 70's I saw one, a couple free love folks started a live off the land movement. Theirs was a large drum with what looked like rubber spikes attached to this drum. When they fired it up and put the to be plucked chicken to the drum, the feathers flew!. The couple with the chicken were covered with feathers and the curious watcher was covered also. When they finished, looked like I need a turn on that -- (I can't say that)-- drum.
Powderbourne Preserve has a bird plucker that looks like a washer drum with rubber fingers inside. Dip bird in scalding water and put a few in spinning drum with running water for a minute or two. works great
Just looked in to this last week. Bunch of em on youtube. Some even use an old clothes washer. Some seem to work better than others. Looks like the drum needs to spin pretty quick and the motor needs some torque to do it. Not sure where they get their rubber nubs for in the drum, but one guy used some old hose pieces. Remember that you're cleaning food, so clean parts to start with (new from the store doesn't mean clean - no telling what the Chinese put stuff thru in manufacturing) should be important.