OK guys here is an "idea from mom" that actually worked !!!!
I use the re-fillable cartridges most mornings (its a LOT cheaper than real k-cups, those are for a "special treat" only) but have been replacing them about every 3 months or so due to the micro-screens getting clogged up.
Ma gave me the idea to soak them in double-strength cleaning vinegar for about an hour then scrub them with a toothbrush. It worked like a charm. They came out like new, and the bowl of vinegar they soaked in got used for this months de-scalling runs.
Since I keep 6-9 of them around all the time, thats about $25 saved this morning, which means my next 12-pack is technically free !! (just go with the concept, OK
)