I'm pretty religious when it comes to cleaning my system.
(I use CLR for it as well as my washing machine and dishwasher 1x a week or two).

It always bothered me that I couldn't clean those very skinny needles, though.

Well, when i used one of these "rinse pods", I could see and hear the action.
The sodium-bicarb/citric-acid foams up and cleans not only the needles,
but the k-cup holder area as well.