Can these heads suffer some kind of unseen damage that would render them inoperable or "less operable" as it may be?
They are VERY simply engineered.
Here's what I do. I clean them, first, in my downstairs sink with a little hot water and some good pressure. Then I blow them out with compressed air. They're now clean and the blades are checked to see if they will still function, properly. I then spray them with WD40.....and let em sit. Then....I'll blow the WD40 out.....sharpen the blades.......replace the O-ring......and put 'em back ona good huntingarrow. Spray 'em with some e3 and they're ready to go.