I've settled in to using the cartomizer on the Leo exclusively. Before I fill it for the first time, I cut off about 1 1/4" of the fill. Every so often I carefully run the straight prong of a bobby pin up through the center and lightly scrape the inner tube to clean out any crud. Then I top off and I'm good to go. Still don't care for the wide, thick mouthpiece but that's my only complaint. The flavor is phenominal on these. I've used the same four (each with a different flavor) for over a month now, I think. Never have to clean the filling. Never had one die. I'm a happy camper. My 801 cartridges for the Leo and tanks are completely unused. Hopefully, Boge will get the new tanks right - but until then, I delighted with the cartomizers now that they're broken in.