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Use Isopropyl alcohol to remove the sticky rubber residue on old computer peripherals and other gadgets. The once smooth grippy surface reverts over time to its natural liquid state, much like it was when it came out of the rubber tree. I don't have a solution which leaves the rubber coating in place - if you've got any ideas, please add them to the comments.

A blog post on reversion:
https://www.polymersolutions.com/blog...