They supposedly hold 2.5 mL. To clean, the easiest thing would be to use a paperclip, and stick it into the mouth-piece air hole, and carefully pry out the end. Inside there is the plastic plate that has the syringe holes, one of each end. Again, use the paperclip to carefully pry that out. It will look like a flat long rectangle. Now the filler is exposed, and you can soak it in alcohol or you can try to boil it in water for a while. I don't know how the plastic housing will hold up to either, but those are the only ways I know how to clean a carto, and both may have downsides. I have not cleaned mine yet, but when I do I will test either method with one, see how it goes, and then do the others accordingly. realize that cartos are meant to be refillable, but disposable, so they are not designed to be cleaned easily.
To boil them, put them in water, bring to boil and boil them on high for 15 minutes. Then change the water and repeat the boiling. Repeat this about 5 times. This is for regular cartos...not sure how these will fare.
I have also soaked cartos opened up in vodka, generally overnight or longer. I have found this does a reasonable job of removing flavors and gunk, but in several instances the carto came back dead. So I boil mine now, and have not had this issue. I think the alcohol dissolves something inside, but it could have been just that the cartos number was up.
Good luck!
