Ewww... I haven't had that under my caps ever since I started paying attention to my keyboards a couple years ago. I re-clean as soon as I notice any particles on the plates. I got this super gunky old Dell keyboard at work for my new terminal, and after I struggled with cleaning it for half an hour (it was impossible without thoroughly soaking), I had it exchanged. Can't use that anymore. Also, I used to have a girl sitting next to me and using thick hemp cream on her hands a few times a day. I wouldn't touch her keyboard with a 10-foot stick.