The propellant used in some brands of silicone spay contain Acetone, (CRC Heavy Duty Silicone spray 30% - 40% by weight) and Methylene chloride (Jig-A-Loo 30-60%). As you may know Acetone is a solvent for polystyrene, polycarbonate, some types of polypropylene, and ABS, so basically all the plastics used to make keycaps switches and cases. Methylene chloride is used for
CHEMICALLY WELDING ABS together.
here we have my well loved and used rubik's brand rubik's cube. I solve this puppy at least 3 times a day, when i first got it like all rubik's cubes it was stiff as a board and impossible to turn with any speed so i went out and got some CRC Heavy Duty Silicone spray. about a week later one of the little cubes popped out and you can imagine my surprise when i saw THIS!
the acetone in the CRC spray did as advertise and had slightly dissolved my cube, it was also pitted and rough and has micro crack running through it
I haven't used CRC for lubricating anything plastic ever again and god forbid what would happen if i used Jig-A-Loo.
so in conclusion if you want your keys switches and cases to look like that go right ahead use a silicone spray lubricant, its a highly effective lubricant that has a long lubricating life. Im not sure if there are any silicone sprays out there that dont use those two chemicals as propellants, there must be some.