I cannot say anything about the MX Ergo. So far, my MX Vertical hasn't gone all sticky on me (yet?).
What worked for me on other sticky plastics was rubbing alcohol. I does leave the finish slightly different than it was initially (less grippy), but I've had good results.
What worked for me on other sticky plastics was rubbing alcohol. I does leave the finish slightly different than it was initially (less grippy), but I've had good results.