From my understanding, you are looking for a juice delivery device to test sample flavors with.
First of all, from an economical investment viewpoint, cartomizers (or cartotanks for that matter) are not a pratical choice. Once a flavor saturates the polyfill of the carto, it pretty much stays there. So unless you like the flavor in it, that carto becomes a throwaway. (Unless you want to go through the time and trouble of trying to clean them.)
You could theoretically use a clearomizer-type device, but all of them that I am aware of are not totally juice friendly from the aspect that some flavors can attack the plastic that they are made of, causing them to crack, melt, or leach into the juice. Most of these flavors are cinnamon and citris flavors, but there are many more.
http://www.e-cigarette-forum.com/fo...-crack-tanks-ce2s-clearos-33.html#post8158663
The vivi nova type tanks are kind of hit-or-miss. These would be easy to fill and clean and then refill with another flavor, but depending upon their construction, version, and model they might be made of the same plastic vulnerable to certain volatile flavors. There are also many people who believe that they mute certain flavors, which would affect their usefulness in testing flavors.
Dripping atomizers are said to provide the best flavor production. However, I personally never got the hang of using them. I found them to be messy and time-consuming. However, if you can get them to work for you, they would be a fine method to test flavors with.
I personally use ce2/ce3's to test flavors. These are relatively cheap - typically around $3. The newer versions are easy to fill, clean, and refill; so they are re-usable and therefore are practical economically. It's been my experience that they produce good flavor representation, and appear to be safe for use with volatile juice flavors.
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