Ok, I just did a little experiment. I had a carto that has been sitting for about a week drying out, and I haven't gotten around to cleaning them yet. So, this one had the Atomic Fireball flavor from FSUSA in it last. It was a tad damp still, so there was a small amount of that juice still in it. I am thinking maybe 2 drops at most. So I willed it with the Maiden Coffee from Gourmet Vapor and wow. It's really good. If anyone has those flavors, I'd recommend it. It's almost like a strong cup of coffee with a cinnamon stick in it.