Coincidentally I also arrived at a 3000 via a 630 then 2000. However I have to report that I have never suffered from this problem.

Are all the key gaps regular? Do you work in an especially dusty / sandy environment?

If the keybed is irregular or you think you have bits between the keys then the keybed isnt that hard to dismantle; I had to do it on my 630 due to a fluid spillage. Once apart clean all the keys with a suitable cleaner, nothing too harsh or scratchy. I've used glass cleaner spray before now.