Just an FYI, I use Kester 44 and the 'secret' to removing flux residue is to: 1) clean as you go, not at the end and 2) after the acid (or tooth) brush and IPA, drop a piece of your lint-free cloth of choice over top and use the brush with a bit of fresh IPA over top - works great.
As far as flux remover, I hate that stuff... Its very aggressive on your skin and you have to use a ton of it.
For the 331, I'd imagine hand washing or even dishwasher will work but I'd hate to see results of the 'glob' that got away.