oh, well, we texted on this already but for others--i throw the carts (okay, i PLACE them) in a big mug or a bowl, and then i pour just off boiling water over them and let 'em sit a min or two. then blow 'em out, then rinse (sometimes if they're really being stubborn, i'll set them in a bowl of water and suck water through them with the syringe--ry4 seems determined to gum up in there), then i dry overnight. well, i dry until dry, but because i do a bunch at once, i just tend to leave 'em overnight and refill later.
again, i know i am probably way too meticulous, but since i started doing this i have had perfect performance from refills, at least ones i didn't like, actually break, lol.