I don't really know about the ego cartomizer or the system.
If you can find Boge soft tip cartomizers that will fit them, then that is the way to go.
You pop off the end rubber tip and drip directly from your juice bottle into the cartomizer.
No needles needed and very very simple.
But again, do they fit the ego,?? not sure.
Try over in the cartomizer forum and see what they may have to say as well.