I was plenty concerned about this myself, but I blew through $80 worth of wired controllers finding the best way to change the color of these things so I present you with the following:
I completed this project Tuesday night, its now Thursday night, a little more than 48 hours later.
I JUST took this video.
For the record this was the third video I took, each scratching the same spot, I was trying to get a clip you could see as clearly as possible, so I scratched it hard three times.
And this is a picture of that spot on the controller afterwards (and you can see in the video that my thumbnail is kinda bending at the end there, I put a lot of pressure on it!):
And this is a picture of the same spot, moment later, after a damp sponge and drying it off with a paper towel.
The only way I have been able to scratch this is by using a flat blade screw driver and just flat out intentionally scratching it, which would have DEFINITELY scratched the original.
I have NOT been able to damage it with just my bare hands, I can literally grab it and claw at it as hard as I physically can and nothing happens.
So if you have problems, I'd say you either probably didn't shake the can well enough, didn't go slow enough, didn't coat it well enough, didn't let it cure properly, or coated it too quickly.
If you shake the can, and do everything properly, aside from intentionally trying to do it harm...I dunno.
