I have one of the models with a clear plastic water tank bought in 2014/2015. The pipecleaner is a good idea, but in a pinch I used a wire twist tie this is coated with a thin coat of plastic. There are several areas I made sure to clean: The filter hole looks like an X in the water tank, just wiped out littlescreens too, then the two things that !$$&* a hole in the K-cup. Sometimes the wire will go straight through to the other side, try to get the wire going UP the big !$$&* hole and down the smaller !$$&* hole. Also cleaned out the little X hole where coffee comes through to the mug. I ran two big mug fulls of vinegar and then two(or more) big tanks of fresh water through the system to get the vinegar taste out. This worked for me. Good luck to those who still have their original Keurig!!! Any more directions here's my email ltlee@gmail.com