Kate (Cathy) Johnson wrote up a piece on the Artists Journal Workshop forum about pens and cleaning, and several folks, including me, discouraged the use of vinegar, as it is rather corrosive.
The Writers Bloc blog has a good write up that could easily be followed, and which I prescribe to for the most part.
This discussion couldn't come at a more propitious time as I am in the midst of cleaning about 30-40 pens, many of which are of the fountain pen variety, others ball points and several mechanical pencils.
I am assigning myself tasks. Each task must be performed for a minimum of 1/2 hour; no maximum. It appears that some of the pens that I thought were cleaned, were not as clean as I imagined and they require much more rinsing, and ear syringe flushes, thus this task will far exceed my minimum.
When these pens are thoroughly clean and checked, I will photograph them and offer them for sale.