feels it necessary to point out that using a larger gauge needle purely to prevent blocking is somewhat counter-productive, as it'll be harder to get the hit in the first place, and mess up your veins much faster, so causing more chances of your future hits blocking before you can get them...
However, if you've got some blood in a hit whilst using a small guage insulin-type needle, and it's starting to congeal, try squirting it out of the pin before
it blocks, add a bit more water, a little more citric, warm it up a bit
, not a lot, don't boil it or anything, and you should be good to go again.
SWIM has noticed in the past the vastly differing thicknesses of her blood from one day to the next, depending on how hydrated she is, how well she slept, how much she's been using etc...so sometime her blood is really thick, and blocks pins quite quickly, and other times it is much thinner. SWIM guesses this could be given as another reason to look after oneself, and eat, drink and sleep well.