are they the prefilled j188 carts or empty? I don't have a VX2 but my roommate does and I have used it. In my experience with it, you need to be REALLY careful not to put too much in. We use a paper clip stuffed down the side of the cart to compress the material. Drip from the bottle as you let up on the paper clip. This soaks up as much as u can get in there. Then flip it over and dab it on a paper towel if you have any extra fluid on the tip.