I found a video on YouTube about using a baby syringe to flush the carto and then like 45 pumps to dry it. I got a baby syringe at a local drug store for $1.99. Have not tried the method yet, but looked fairly easy and the equipment needed is certainly cheap enough! Also showed to use an oral soft pick to swab the hole in the carto. I googled "how to clean a cartomizer" and that was one of the links. Sorry I don't have the link handy.
I've done this and it works to some degree...but the filling is still damp. It's a good start, kind of like spinning, but still not totally dry.